Is it worth the maintenance and all the extra costs?

Don't forget to determine how much deferred maintenance there is - i.e., how much will you have to pay to keep the properties maintained when you first buy them or within the next few years. 

When I account for 10% vacancy, 10% repairs and maintenance, 10% CapEx and the numbers above I end up losing money every month.And I know I could argue that I don't need to account for capex/repairs and maintenance as it's completely rehabbed, but I have the understanding that the deal should cashflow anyways with that accounted for.

Is it worth the maintenance and all the extra costs?

Nothing wrong with the concept but not strictly the business portion of what we are into.I would never invest in SFHs due to the higher risk, higher maintenance, and lower monthly return but I have always held true to the concept of "income investing" and I have done very well by it.

We basically offer all of the services of a turn-key company without the commitments.

Huge red flag, never exchange any monies owed for services unless the tenant is a hooker and you get the service up front.

No idea what the $650 is for.very fast talker and gets upset really easily when you question his service.

Income and Costs (all numbers are annual)Nominal rent - 43.6kActual rent - 37.3k (14.5% vacancy.  33% turnover rate)Management - 4.5k (10.6% - could bring down with a PM switch)Maintenance - 5.0k (11.6% - ok, older building and a fair amount of tenant turnover)CapEx - 2.4k (5.4% - mostly plumbing costs: is that a worry?)

It looks like you're already in Birmingham, so a quick drive around the neighborhood shouldn't be an issue and can save you a lot of headache in the end.If the Calera property adds up without relying on appreciation, and you have already done due diligence on what the rehab consisted of, who's selling it and what their performance metrics are like (tenant turnover, maintenance rate, occupancy etc) then that is the best of your two current options.