In contrast, the average sale price for Co-ops is less than half at $313,000. 

I bought it in cash since it seems most banks don't work with Co-Ops. I

I wish that were not the case but I look and look and look and can't see how I'd buy anything that would cash flow or give me value add ops.  I

On a 3 unit I would definitely not go with sets of coin ops, I think that is overkill.If it were me I would explore in unit. 

Whether I can have a hotel operator as a tenant or otherwise find a way to outsource the hotel ops is a critical assumption. 

Normally this list would include the PI part of PITI (Princinple, Interest, Taxes and Insurance).TaxesSewer and WaterTrashHeat/UtilitiesHOACap Ex and Ops (I always budget at least $150 per month per roof)InsuranceMgmt Fee - as a % (general consensus here on BP is 10%. include it even if you think you are going to self manage)Vacancy- as a %. (8% represents 1 vacant month/unit/year)

Sellers tend to underestimate the costs of heat and hot water if they are the ones paying for it)HOACap Ex and Ops(I would double this number for building 1 against building 2.

You could also try partnering with a private lender/investor that's willing to sponsor the deal - but be mindful that investors are already wary of buying co-ops as the main purpose of co-ops is to discourage landlords/investing and instead allow homeownership to regular folks. 

The issue with second mortgages and HELOCs specifically on co-ops is that there is only one stock certificate and one lease to hold.

opsI forgot the excellent Joe Fairless blog and his podcasts.