It's not a problem at your level. At level 50 and higher you find stuff you can sell for 2K 3K and higher. No one can buy this loot. This is the problem. Well you're going to be rich by then so it's not really a problem. It's just lame.
"Can sell for" is the key.
I'm already finding stuff with base values of 1000+, including items with base values of 1800-2000. They tend to actually sell for about 800-900, max. Sure, that means I deplete one vendor right away, but as I noted, in Whiterun, there are several with enough cash to get rid of all my stuff.
But as you say, cash is not a problem . . .I'm running around with approximately 120,000 in gold right now. The only thing I ever buy is health pots . . . there's nothing else I've needed to buy in this game. So even if I was selling a 3000 gold item for 800, it would be no big deal.