Spencer Gifts used to sell a couple of small ones, which is what you want. They could be had for under $10. I have no idea if they still carry these. Actually I don't know if Spencer still exists, but they used to be in every mall.
You can get them from spencer's (in the mall) and they are around $10 to $20 dollars for a more-than-basic one. There are ones that cost more but you really know need a $50 dildo unless you're gonna be showing it off.
You can also google online sex stores and they will usually send them in unmarked, unrecognizable boxes. The prices there vary from $10 to $50+