Our county has listings online for homes that have sold, with a description of the home and the selling price. If you don't have that, you probably can go to a county or town office and research them yourself. It is public information.
Our county does have access to tax appraisal info and tax amounts, but not sales prices...at least online, I have heard it is a matter of public record, but as far as I am aware it isn't available online. Thank you!!!