More and more cats, oh my!

A couple of nights ago it was rather chilly and temps dipped down into the 20's. Apparently the neighborhood cat decided it was too cold for her 5 little kittens. So where does she bring them? My garage. Today I was able to catch them and take them to the humane society. Kind of sad, but they said they would probably have to kill most of them because they are to feral already. First she told me it would cost $60, but thats bullshit. Than she decided to charge me $30. Thats such crap. They said in my neighborhood, feral cats are getting out of control. That they know of, there are more than 100 cats. To my knowledge this black cat has had 3 sets of kittens (thats where my garage cat came from). But I think that this cat has gotten close enough where I can put on some armor and try and catch it. Than I have two options. I can get a voucher and have it fixed for free. Or take it to the humane society and tell them that she has little chance of surviving the winter. Which isn't entirely true, but it sure would be nice to get rid of the problem entirely. Is that inhumane? Plus I fear becoming the neighborhood "cat lady."