The OP's bicycle looks like a PX10 of some sort, to me. True, the Reynolds stickers are gone, but many, if not most, of the frame and component features do suggest a PX pedigree. Value..?

Were I given the opportunity to buy the bicycle (assuming I could afford to do so), I would not bat an eyelash at $300.00. I would go as high as $500.00, if my plan was to keep the bike. I can say this because I have both the skills and replacement components to restore the bicycle. It is the frame/fork set that catches my eye, not to mention some very nice components, as well.