Hi Marlo, and welcome! That data doesn't exist as a list, as far as I know.
If you do a random search, you'll see that prices vary from incredibly cheap, to more expensive. I personally feel that some people are underpricing their work, but the good thing about FAA is that you are free to set your prices to whatever you feel buyers will pay, or to whatever you are happy to accept.
One way to get a feel for prices is to do a search for images similar to your own, and see what the competition is charging :-) Depending on the standard of the competition, it might be a good place to start. The FAA markup for sizes between 16" and 60" is around 40%, so just deduct that to get an idea of your price to set.
Also, if you do a search for say 'beach umbrella', you'll see starting prices between $17 and $73, but some of the sellers are not offering smaller sized prints, so obviously their starting prices will be higher.
Personally, I don't offer small prints - too easy to scan, and then claim a refund. I also price greeting cards high, to deter people buying them and putting them in a cheap frame to hang on their wall - and they still sell!