Well these listed prices are asks, not bids, so they only give an upper bound on the value. I've tried to sell obscure things before where there are few or 0 other sellers, and no matter what you list it for, you might never find the buyer who wants that specific thing.

And the electronic shop is probably going to fetch a higher price than an individual seller would, due to trust factor as you mentioned. So have you managed to sell old Windows PCs for decent prices in some local market?