I got my start in reloading similarly ages ago in college – reloaded for a Garand for service rifle matches, and for a few revolvers for IHMSA silhouette. My first mistake when starting was going right to a little Lee Pro 1000 progressive press for the pistols (not big enough for rifle, briefly used a low cost Lee C-frame single stage press for that) – while I eventually got a fair chunk of my money back out of it when I sold it, 20-20 hindsight says I never should've gone there to begin with. After getting frustrated enough with the Lee, I picked up a used Pacific (now Hornady) 007 O-frame single stage press and have never looked back. Bought another progressive setup later in the form of a RCBS Rockchucker and Piggyback II combination, but once again frustrations returned, so back to the trusty 007 I went (and have remained).
My recommendation - start slow with a quality single stage press setup, and learn the process thoroughly before trying to increase speed/ammo output. Even if you eventually move on to a progressive, you'll still want the single stage for load development. As far as cost-effective? Its been a really long time since I checked on actual costs (haven't done any reloading for a few years due to other priorities), but I know I used to load a box of 50 30-06 for well less than what 20 would cost off the shelf, and .357 for below a ¼ of new.
Equipment-wise, most everyone out there produces good stuff, some is just a little better than others. CH, Dillon, Forster, Hornady, Lee, Lyman, RCBS, Redding, are all quality manufacturers. I'm not a big fan of the all-inclusive starter sets, as there are differences in functionality/ease of use of different pieces – like hand tools, nobody has cornered the market on making the best of everything. If possible, try to swing by one of the big box sporting/outdoors stores like Bass Pro or Cabelas - they typically have the bigger stuff set out for display.
Load Manuals: Get a handful of current ones, not just one, so you can cross-reference load recommendations. There can be a surprising amount of variation between the same powder/bullet combinations between manuals. Lyman has IMHO the best general manual around, with the powder manufacturers being preferred sources as well. Several bullet manufacturers produce load guides, but they tend to concentrate on their particular bullet offerings, which is fine if you're using their bullets. There are also online resources available for use from the various component manufacturers.
Press: While Lee is well known as a “value-priced” line, if I was looking to replace my 007 with something other than another 007, I'd take a hard look at the Lee Classic Cast O-frame press. The Rockchucker I have doesn't have as much internal clearance as either my 007 or the Lee – something to think about with a long cartridge like the .30-06.
Powder Scale: Keep the powder scale simple with a beam scale like the RCBS 5-0-5 (which I use). Avoid electronic scales for starting out – they have their own little quirks and issues that a beginner shouldn’t have to deal with (I've got one as well, but don't use it for powder). Also get a set of check weights, as you can't be too careful when keeping powder measuring equipment calibrated.
Powder Measure: While I'm definitely no fan of Lee powder measures, most of the other brands' measures are very similar in construction and operation to the RCBS measures I use.
Dies: I've got some from most everyone. Personally, I tend to lean towards RCBS, Redding, and Forster for rifles, and Hornady for pistols. Lee is once again the “value-priced” source, but I've had issues with rusting on Lee's that I haven't had with others. Lee also uses a lock ring that locks the die to the press instead of the ring to the die – IHMO a real pain because you need to re-adjust the die every time you swap it in. For the Garand, you'll need a full length sizer die at a minimum, with a small base sizer die preferred.
Priming: There are several different methods out there ranging from on the press to handheld to a separate bench operation. Personal preference is for a Lee Auto Prime II, which sits on top of the press and primes on the up-stroke instead of the down-stroke – it has a quirk or two to be careful of, but I've been very pleased with the very consistent feel and results.
Misc: Case tray to hold processed brass upright while moving through the reloading steps. Primer pocket brush/cleaner. Lube pad/spray for rifle cases. Case gauge to check for over-length cases that need trimming (and to check for proper full length resizing). Case trimmer and case mouth reamer to trim cases down to specs if/when needed. Bullet puller/kinetic bullet remover. Calipers/gauge to measure overall cartridge length. You'll eventually want a small tumbler for cleaning cases – dirty cases scratch/foul the dies. If you're using once-fired unprocessed mil surplus brass, then you'll need either a reamer or swager to remove the primer crimp before priming the case for the first time.
Unless you're in a real hurry, you can definitely find savings by looking for used equipment. The only stuff I'd really look for new are the dies, powder scale, and the small/cheap misc stuff. Midway, MidSouth Shooters Supply, Widener's, and Graf & Sons are all good online/mail order stores for supplies and equipment (MidSouth more often than not has the better price IMHO).
Dang if that wasn't long-winded......
Oh ****, a few last comments about loading for the Garand and mil surplus brass. As stated above, mil brass is slightly smaller inside than commercial brass, so loading the same powder charge will result in considerably higher pressures in the mil case – BE CERTAIN you are using powder charge recommendations for mil brass when reloading mil brass. Mil brass also MUST have the primer crimp reamed/removed before priming the once-fired case for the first time. Finally, if you don't know what the brass was fired in, then you should definitely resize it the first time with a small base sizer die. Those are the negatives to using mil surplus brass – the benefits are that mil brass is normally cheaper to acquire, the case necks are annealed and run through the dies much more smoothly than commercial, and the case is overall thicker and stronger and should last longer under normal shooting and reloading.
The Garand gas system is very particular to a specific powder burn range – too fast or too slow a powder and you'll have cycling issues at the least to damaged op rods or worse. Lots of info available on the web, research it thoroughly.
Reloading really is a fun (and safe) hobby – just understand the (potentially) serious consequences of what you're doing if you fail to do it properly. Pretty much like anything else we do for fun or work.