Extra Manager's fee / Legit ???

[Dan DeAngelo]

I have a 20 and a 19 unit property that is professionally managed off-site.  I pay 7% of collected income and my manager also charges leasing fees, trip fees, and recently another fee that really bothers me.  The new fee is the difference between a wholesale fee, or discounted fee, a vendor charges them for a repair, because of their relationship, and a "market rate" for that same repair from a vendor who doesn't give them a "relationship discount. Basically, they expense to me a manager's fee for the difference between a wholesale repair cost and a retail repair cost. This is hard to measure and I just don't like it.  My manager says this has become common in the market.  Any ideas on 1) Is this a legit fee and? 2) What better compensation system can I do to better align their interests with mine?  Thanks.