I maintain my position that there is a vocal minority complaining here, and the vast majority of players thinks different. Why else would 50 gold still be a standard price for unique items? You can buy a small unit from that.
50 gold may be a decent sum for a lowly knight, but for a duke or other person with high income, that's pocket change. If I was an adventurer looking to sell an item, I'd probably be offering it to the rich people in the realm, and trust me, unless the realm is doing poorly in a realm, they're not going to care much about a mere 50 gold.