For that few of a number of snakes, no, it probably wouldn't be cheaper for you to raise your own than it is to buy them. It can be and is for me, anyway, a satisfying endeavor to raise them up and know what's been fed to them and how they've been raised before you feed them off. If anything I spent more just building the rack to house some of my feeders than what I would have buying frozen. If you have picky eaters that will only take live then it might be worth it but if all of yours feed on f/t, they all eat the same size feeders or similar and you don't mind storing f/t in your freezer, you're more than likely going to be better off sticking to that rather than raising your own.

I feed mine Native Earth 4018 and buy it in the bulk pack from National Pet Pharmacy; the cost of the food alone is about equal to what I was spending to buy frozen feeders. I have plans to breed mine at some point and I have one diva female who will only take live, when she eats anything, so I don't mind the hassle of raising my own. It can be a lot of fun when you get into the genetics of them: dumbo versus standard ears, Rex, Double Rex, standard coat, Manx versus standards, etc. and the results of their breedings are waaaaaaay faster than what raising snakes is. Ultimately it's your money and time you'd be investing so ultimately it's up to you. That's what my experience raising them has been, thus far. Not trying to talk you out of it, just give you an honest assessment from my perspective.