Plus, if the buyer sees that he is getting charged from the other wholesaler as well as you, he might back out if he feels like he's getting a bad deal or is being overcharged.

@Kewei Qu  15 percent overcharge on repairs is not typical..

I had to request a refund for the overcharge multiple times before receiving it.

It helps you gauge whether the tradesmen you hire are doing a good job or missing details or overcharging or goofing off.

Truthfully, my mental energy would be better spent pursuing other deals and opportunities rather than worrying if the painter I hired is over-charging me by a few hundred dollars.

I used "really good" PMs and yet they could not fill vacancies, they over charged for stuff and used terrible subs that overcharged.

My issue is the local plumbers are significantly over charging.  

It’s about asking the BP community whether or not I’m being overcharged for this service, which is one of the great things about having a platform such as this to turn to when you want to make sure you’re not being taken advantage of.

They overcharge for everything, and seem to do very poor work.

In this case his profit is attached to the company's therefore he'll do everything in his power to make sure we're not being overcharged.