In some cases it is clearly abuse. In other cases, there is little distinction between abuse and competition due to the snowball effect.

Imagine that today you need $300 to be on the Trending page. What if someone spent $1,000? Today we consider that abuse and would flag it. In the future the snowball effect will drive the minimum price to $1,000 or more just to be on the HOT page. The question becomes Was it really abuse to have spent $1,000? If the minimum price to be on the Hot page is $1,000, then is that abuse?

If you ask anyone that can't afford today's minimum upfront cost, they would confirm what is going on currently as abuse.