I have 4 FW's. Price paid was $3 from a yard sale (ad on CL) for one that was totally siezed up everywhere possible, and 3 for $100 ea bought off CL at different times. They were all pretty sad looking when I found them, but they are all fairly nice and extremely useable now. The thins is, many ebay units are spruced up with every accessory in order to command the highest price. But maybe if you just want one toa actually use, you can find one cheaper. They aren't rare at all, there were millions made. They just have an almost cult following now, which drives up the price.
Good luck in your search, GW isn't bad, but you don't know the condition of bobbin case and base and needle plate and motor, any of which can set you back $40.