This is quite literally a problem that occurs in EVERY freaking game. Shoot, It even occurs in REAL LIFE. EVERY DAY.
In any free market, The price is just naturally regulated by Rates set by distributors and if the intended market is willing to purchase for said price.
If no one thinks that its worth to buy for 7:100, then they aren't going to do it as liberally. If they find someone who just happens to sell the exact product for a cheaper price, then of course they will go for it. That's something that EVERY distributor has to be mindful of when selling. Which is why so many people regularly check market after they list an item to see if they have the cheapest listing or they have been undercut.
Its just a matter of either you have whats considered better quality (in the game's case: better stat rolls) or you have whats cheaper.
Which brings me to my question:
Which maniac decided that the extra 1% between 2% Crit Dmg El Tears and 3% Crit Dmg El Tears was worth an extra like 50-80m?