Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
There's really not enough information to give you a very good estimate. In the end it really doesn't matter anyway because the real value is determined by what a buyer is willing to pay.
By comparison: Brand new Ultegra/Open Pro wheelsets are typically available in the $250.00 range for front and rear. You can buy the whole wheelset cheaper than you can buy the component parts to build yourself. I'd have to rate a new such wheelset as superior to any that you pictured and your's may be used to boot. I'm thinking that $75.00 to $100.00 for a rear and around $75.00 for a front would be a fair price. Now all that you have to do is to find a buyer.