For my 10 babies, I have sterilite shoeboxes. $1 each at Big Lots. And for their water dishes/hides, the smallest plastic "nibble bowl" things in the Small Animals section at Petsmart for 99 cents each and empty paper towel and toilet paper rolls (free!). Paper towel substrate, and a $30 bookcase from Walmart to hold it all. They don't have supplemental heat just yet (my room is kept in the 70s), but I have a couple Bean Farm heat pads in the garage that came with a wooden viv I never ended up using (around $20-30 each, retail) that will solve that problem once I get around to scrubbing them clean and chase down a new thermostat ($30 for an Alife, again, from Bean Farm) at this month's expo. This whole thing will accomodate 18 hatchlings (6 per shelf in the top half of the 5-shelf bookcase), and easily 12 or so more when I get more heat pads or heat tape for the bottom half of their bookcase--just a matter of throwing together more tubs and hides for $2 each! =)
For some of the bigger guys... I have three 75 gal tanks. One was $60 off Craigslist, another was $20 (with stand and screen!) from a local auction, and the third was free (again, with screen!) because Hobbs' previous owner had no use for it... The only real expense on these was the screen for the first one.
One of my 20Ls, with sliding screen top, was $10 from CL, and another was free with my (rescue) beardie.
Yet another 20L with sliding screen top was $20 from CL.
I have a 10 gal with a sliding screen top that I picked up (with mouse stuff) for $5 at a garage sale.
A 29 gal with sliding screen top that came with a heat pad, 3 heat lamps, hides and a thermostat that were practically free with my female boa ($100 total, but Osiris alone was worth more than that).
My two Exo-terra vivs, while still expensive, were purchased at considerably reduced cost because the pet store couldn't get them to sell, yet even those can be found all over CL at decent prices...
Oh, and some of my newer snakes were housed temporarily in 15 quart tubs that cost $3.50 each at Big Lots.
One of my favorite hide ideas for the sub-adult/adult corns (and similar-sized snakes) is cottage cheese and cream cheese tubs... Other, similar tubs work great, too--I have an oyster tub for weighing smaller snakes and a shrimp tub for the male Dum's water dish, and I'd use cool whip tubs if my family ate the stuff more than once a year (pumpkin pie, yum!).
Shoe boxes and similar stuff make great hides, too, for the bigger ones (ball pythons, sub-adult boa constrictors...).
I could go on, but I think my post is long enough... Lol!
What a great topic, though. Housing snakes really isn't as expensive as one may think. You just have to know where to look... Or at least have a good eye for "alternative uses"! I think I drive my parents insane sometimes when we'll be walking through a store and I'm pointing at every other thing and saying "Oooh, that'd make a good hide/water dish/tree/enclosure for [enter reptile name/species here]!" =)