Try garage sales? We've had pretty good luck for jumpers and things like that. We have a crib, a pack n play, a swing, bottle warmers and clothes, a walker, car seat bases, car seat, etc... We got all of this for under $40 just at garage sales. But about his complaining, tell him to man up and support you because it takes two to make a baby. Tell him that by getting uses things your probably saving hundreds of dollars that could go to a bill or something like that.
Boys have so much pride! I suggest letting him buy a few things. And the more expensive things buy used. Explain to him and try to see his side as well. If he still gets mad I would personally keep buying them because you know in the long run it'll be best. Show him why it's best to buy used-like go shopping with him and let him see how expensive the crib and stroller is haha!!
try once upon a child if they have that store where you are they have alot of gently used baby stuff and cloths for great cheap prices