Consider for a moment, that you are a writer. You offer your lowest price at a discount. Say, the first 500 words is 5$, but each extra 250 words is an extra 5$. Something like that.
Now consider that someone sees that initial 5$ for 500 price, and decides to take advantage of it. Ordering several smaller orders and breaking up a single article into multiple smaller segments to save some cash. That way, instead of having to pay 35$ for 2000 words, he only has to pay 20$ for it.
Considering that this is a hypothetical scenario. what would you do?