Credit union is offering 6.5% mortgage loan for multifamily property. 

I figure the interest only payments for land loan would be roughly $2,100/mo. (800K @ 8% for 3mo).

Has anyone used https://www.umeprojects.com/ for loan assumption?

They may need to pay their agent out of their own pocket and they may not have the money for that in addition to the down payment (buy-side commish is usually baked into the sales price and paid at closing from funds to the seller, so the buyer can roll it into their loan and finance it rather than paying out of pocket).

@Kayla WeigelCommercial loans are the way forward. 30Y DSCR and rehab loans.

We are selling a house with part loan, part contract /seller buyback. 

@Mark Kiser I have heard people dropping $25K for a mentorship program and taking out a 5 year loan on it. 

You can expect anywhere from 7-9% on a DSCR loan.

Neither does the amount of loan that you have on the property. 

HELOCs aren't like Fannie/Freddie loans where everyone is following the same rules of the road very closely with little variance.