It really depends on the condition and what type of beanie baby it is. Some are limited edition and those are worth more money. If your buying a beanie baby they aren't too expensive ranging from...
Niles the Camel is worth anywhere from 1-10 dollars you can find it for 2 dollars and up at http://www.amazon.com/Ty-Beanie-Babies-Niles-Camel/dp/B00004TFW5