Wal-Mart sells a LexMark 640 for $25. It comes with an ink cartridge (new cartridges will run you $35). I used one to print out 250-300 pages of a novel (I now have 3 LexMarks, counting the one I bought for my mother which she never uses), an old Epson C80, an Epson 1160 (that's my baby - it'll print up to 13" wide by 44" long), and a Canon BubbleJet.
With a LexMark and a full cartridge, you're costs are $0.12/page so it's not the best way to go.
Color printing is what really costs you, but you can print B&W for around 1/4-1/2 cent per page. Since it's for editing, set your printer to output at a lower quality print to get more life out of a cartridge.
If you really want to amortize well, go buy a laser printer. It'll set you back anywhere from $100-400, but the toner cartridges ought to give you somewhere around 2500-3000 pages (at about $100/cartridge or $0.04/page) before you need a replacement.
In all cases, a home printer is a lot cheaper than going to a copy shop. I'm not certain, but a case of paper shouldn't run you more than about $25 (for 5 thousand sheet or about $0.005/page) and it's something a writer needs to have a lot of on hand anyway.