They use leverage in some of their funds, which can increase returns, especially if they have a low cost of capital (but potentially increase risk and trigger UBIT issues).

Be conservative on your rehab budget, rehab timeline, holding costs, etc.

Others may argue that higher rates are bad as it drives up their borrowing costs. 

If the tenant is claiming to be living in a hotel, she may try to get you to reimburse for that cost unless section 8 has a new process to reimburse them for this... which sounds absurd but I'll let you deduce whether or not you're dealing with someone who is used to paying for things out of their own pocket. 

If you sell the property, a lot of the $107K cost will be eaten up in transaction cost.

This puts the home underwater.I've calculated the following two options: To sell the house, it would cost me about $60,000out of pocket.

No management costs?

Avantstay's services cost money because they provide value.

They will have additional costs for mailing & online campaigns to get leads.

Your cost basis would be ALMOST zero if you ever sold.