I think the biggest issue is not whether or not it can/should be increased, but, how does this effect the economy. Economics is a fragile thing, and altering something as simple as this can have a massive impact on the economy.
Example: If I can sell only 10 things, I will sell it cheap to free up space. If I can sell 1000 things, I will just list and forget it. Especially if I am in no need for the Gil.