I go to a local supplier and
buy in bulk - a hand full or 2 of this size, another handful of that size and so on until I amassed a very good selection. Buying in bulk is So Much cheaper then buying prearranged sets. Hardened Cap Head Allen bolts - $3.50 per lb. Normal Zink plated Hex bolts, nuts, and washers $2.95 per lb. Stainless is a little pricy at $6 - 8 per lb, but still a far cry cheaper then what the local hardware charges
But it does leave the problem of storage because now when I get home I have a box full of medium sized bags of nuts and bolts.
To that I applied 2 remedies - first was this 96 bin organizer I purchased from Northern Tool. I had to order 2 additional sets of bin dividers before I was all done. And I bolted it to the wall just above the footing wall to make it impossible to ever tip over
I have every thing from 1/4" up 3/4" nuts, bolts, allens, and stainless steel
That left the small machine screws - for that I used smaller bins affixed to the wall over my work bench.
Here you can see my son helping to mount them for me
Now one might ask why so much attention to hardware - well make a couple trips to the hardware store buying onesy - twosies or 10 at a time at $.50 to $1.50 for each nut bolt flat washer and lock washer and real quickly you'll know why