I think your prices are good - but for your actual paintings, why not offer prints as well?
I was reluctant to offer prints for a pretty long time, until finally it really started to hit me that once I sell an awesome painting, it's gone forever. All that work, only going to 1 person. So I started getting mine scanned in (I use FedEx Print & Ship Center) and I sell prints - then after all that work I put into the painting, I can sell it over & over.