Seems both are 128ZX. But for 10€ I'd rather keep'em. I feel somehow nostalgic to them as they were the first accelerator cards I owned, and the first that could play Motoracer with the proper smoke effects.
Yes, I also believe that 128zx aren't as desirable as the Voodoo's, hence the voodoo's going >€50, but 10€ for a quite scarce (maybe a bit rare?) card is a bit low I think.