Packard...that's good advice. I think reasonablly priced tap/die sets that are decent quality are basically GONE from the markiet. I have a bunch of the Irwin/Hanson sets, (Snap-on, Matco, and MAC) and they are ****. I've had more problems with the taps than the dies though. My 20+ year old Craftsman sets blow them away in terms of strength and quality.
If I needed a set now, and was willing to look at used sets, I'd look for some of the older Craftsman sets. And if a tap gets broken or is missing, replace it with Greenfield. The new Craftsman stuff is no better than the Irwin/Hanson/Matco/MAC/Snap-on.
I also have quite a few loose, (mostly high quality) taps, and some dies. I always try to see if I have the right one for the job before opening a set. My next line of defense is one of the Snap-on sets. If I break that...then I go to the old Craftsman. My goal is to try to keep my Craftsman set complete...so I always have the correct tap on hand. If I break a loose tap, no big deal. If I break a truck brand tap, it is easly replaced with another medium-poor quality tap. If I break one of my old Craftsman's...that's means mail ordering a tap from MSC. No matter how carefull you are, you will break taps once in a while....especially with the **** they're selling these days.
Also, on another note, most of the newer, rebranded Irwin/Hanson taps and dies are no longer engraved. They are just printed with the size. So after using a couple of times, good luck reading the size/pitch. Now THAT *****.