I'm not sure what they sell for however when their silver they will say sterling on them. Sometimes if they're from another country there will be other markings as well but normally they do say Sterling. I normally put them in a pile and then take them to the recycling plant when I get a large stack. I'm sure that's not the best option to do with them but that's what I do.
Anything made by Rogers, if it doesn't say sterling or 925, will be plate. I've handled probably over 1000 miscellaneous Rogers pieces and I've never found one to be sterling. The odds are probably one in a million of finding a Rogers sterling piece. Most of the sterling pieces they made are well over 100 years old and they didn't make very many. If I have plate leftover from a lot, I'll list all of the pieces together in a lot and throw them on ebay. I add priority mail shipping for whatever box they will fit it, start auction at .99, and let it go. I have always made back over what I had into them.
Silver plate over copper. There are many varieties of "Rogers" marks. Here is yours-
(eagle) WM. ROGERS (star) individual mark of William Rogers used on coin silver spoons (Hartford, CT, 1825-1841). From 1878 to 1893 the mark was used in silverplate flatware by Simpson, Hall, Miller & Co under permission of William Rogers Jr. This mark continued to be used until 1976 in silverplated flatware and from 1938 to 1976 in hollowware