Like Terry suggested though, I would hold off on spending it at least for 30 days to see if the commission tries to prorate it and take it back.

Also consider what they are charging their commission on. 

I don’t know if this bit of information matters but I will be investing with a partner and I will be using whatever commission they are offering as part of the down payment.

I’ve thought about finding someone who could simply handle showing the property and screening potential tenants and just get a 50 percent commission on first months rent for successfully placing a tenant.

Figure about 3% in closing costs when you buy the home (2% commission and 1% in closing fees) and than 7% when you sell (6% commission to agent and 1% escrow, title, etc.)

@Andrew Poitras, from your profile picture, I have no difficulty envisiging you as one of the Agents in "Selling New York" (or similar), where they regularly talk in multi hundreds of thousands in commission - per sale!

I would play this one above the belt, report it to the relevant investment and securities commission. 

Purchased for $9k and seller put in $50k of renovations.Buyer to pay $4000 toward commission at lease signing and seller to pay remaining commission plus seller agent feeSale price of $72,000… Lease payment to be $685 month.Lease payment to have principle reduction as if we had a note for $72,000 for 420 months @ 7.5%

Some states' Real Estate Commission website will list software companies that meet your states accounting requirements.  

We tied the parcel up for basically nothing, and used our commission as a down payment The seller had some terrible concept drawings, that we knew we could rework and did.