"Web domain" will sound redundant to domainers because we think about domains all the time. But I still run into articles about "internet domains" in the mainstream press all the time. So for non-domainers, maybe WebDomain.com will actually make more sense than "domain" alone.
There's also bound to be a lot of interest in .WEB when and if it is released. So WebDomain.com may appeal to whichever company ends up managing that TLD.
I think $1x,xxx is probably the upper limit for this domain as a long-term hold with a best-case scenario. But I've seen domains I thought couldn't go above $10k end up above $30k. So who knows? That's really outside your control. Depends on whether a very well funded company takes a serious interest in this "web domain" or not.
Other than that, I can imagine you'd get offers from retail buyers that could end up in the $x,xxx range. I'd probably peg WebDomain.com somewhere in the mid $x,xxx territory if I were dealing with a serious buyer and trying to manage my own expectations.
Wholesale, you're looking at anywhere between $200 and $2k, depending how you sell it and how quickly you need to sell it.