It's not just a guy thing, I tend to packrat myself. So does DH. At least we have a big barn and attic to fill up.
The rule in our house for packratting is, if you aren't going to use it immediately, don't get it in the first place. When you need (fill in the blank: loose hardware containers, canning supplies, whatever), it will still be at the store, waiting to be purchased. If you're going to get it on sale, or save it for something, use it right then and there. For example, if I'm going to bring home empty plastic containers from work to organize the woodshop stuff, I better be doing the organizing that very weekend, not at some time in the distant future.
Also, for every acquisition, be it purchase or freebie, you have to have done your homework and be 100% sure that this is really what you want. We don't do the whole, "Well, I really wanted XYZ, but ABC will do in a pinch." We have found that nine times out of ten, ABC will NOT do in a pinch, it will require five times the work and fidgeting around that the original XYZ purchase would have required. Chickens are a good example of this: Free chickens from the commercial meat chicken place are not bred for laying, surviving cold winters, or even for disease resistance really. The commercial chicken processor only plans to keep the chickens alive for a comparatively short time through the administration of lots of drugs and hormones and an on-site veterinarian--and presumably you want to keep your chickens alive for a long time without horrendous vet bills. In terms of cheap, is it cheaper to pay $2/chicken for a hardy breed that will lay plenty of eggs, or is it cheaper to pay $70/vet bill every couple of months for chickens that are constantly sick and produce few eggs?
You've heard the phrase "penny-wise and pound-foolish"? Tell him he can be as cheap as he likes when it comes to buying toilet paper, spaghetti, papertowels, sodapop, most household cleaning products, birdseed. He can use his frugality to build you a winter garden with row covers out of salvaged materials, and feel like he is saving some $$ on the grocery bills. Some things though, it doesn't pay in the long run to skimp. Use those mayo jars to make mini-greenhouses for garden plants!