Thousands of Animation cels are available on ebay everyday and sometimes you can get a good deal. Commercial cels usually are the least expensive. I purchased a Tony the Tiger Jr. cel for around ten bucks with matching drawing.  One of your favorite characters like Fred Flintstone can cost little if it is a commercial cel too. But beware, many major characters from "worthless" commercials are be sold as something else. Partial animation can be a steal too. I found a purple arm belonging to Race Bannon from the 1960's Jonny Quest for ten bucks. It is only an arm, but when a full original 60's Jonny Quest cel is $100-$1000 and I was able to pinpoint the exact frame on the DVD where it was!  Japanese anime maybe more difficult to identify, but a great shot of a "unknown" may have a great expression for $5-10. Sometimes you can buy a bulk "junk lot". Probably only a few cels are worth saving. Unless you have a use for the rest they just get in the way. Many of these less expensive cels tend to be authentic because who would go to the trouble of faking them for little profit. Also if you spend a lot of money on a cel, it may still have things you don't like when you get it. But a cheap cel if not satisfactory did not "break the bank".