I am assuming the $500/month neg cash flow is projected with underwriting that reflects all anticipated costs such as maintenance/cap ex, vacancy, pm, taxes, insurance P&i, misc.  

Sustained maintenance costs that are higher than anticipated increased occupancy and nightly rates.

I love the anticipation. 

I would anticipate you would do one for a property that costs greater than $1,000,000.

Which means, as long as the total gross rent covers, the anticipated principal interest taxes, insurance - you will have a greenlight for funding, good luck!

Since it is the smaller unit I am anticipating $6,500. 

Sales price: $900,000Seller finance: $400,000 / 2 year ballon / 7% interest rate / interest only monthly payment: $2,333 / no pre-payment feeEstimated monthly income: $9,300 / Annual: $111,600Electric separated - water $450 per monthProperty taxes: $16,700 (with property value assessed)Property Insurance: $6,300Renovation Repairs $150,000I anticipate the Re-fi appraisal to come in at a conservative $1,150,000. 

My suggestion would be to send the security deposit claim for the anticipated refund minus what you anticipate the bill will be (historical average plus some padding). 

Thankfully buyer was patient and still closed, a couple months later than anticipated.  

But there generally isn't a market for them as such.But that being said once in a while a DST comes on specifically designed for shorter holds and they anticipate an 180 month to 2 year hold.