You're right, whoever is willing to pay. But everything has a market value, even rare items. So if the market value for a 2wd 3rd gen is typically (x) but people are willing to pay

for a good one with low miles, then asking for (z) is out of line. IMHO 20k is out of the market, but I could be wrong. I don't know the market, I am speculating. I just don't think anyone looking for a 3rd Gen 4runner is going to pay 20k!
I'm a big eBayer, buying and selling on there in unique items I find at flea markets etc. One way I determine the market value is to research completed auctions or sales, NOT asking prices. A completed sale is a better indicator of market value, and to date I have not seen a basic 3rd Gen 4runner even with very low miles go for $20k