I have a bi-yearly contract with them to maintain the units and they currently have a new policy where they check for mold in the duct work by an intrusive method and they are finding slight mold growth and are recommending this device called Nasa Air Scrubber (~$1200 per unit). 

No, just 25 yrs of experience being involved in literally thousands of deals and watching realtors do things the wrong way or take shortcuts, loosing deal after deal for my borrowers is what has taught me what works best.Unfortunately, down here in FL, everybody and their mother has had or has a real estate lic. and too many think or lead their clients to think they know a lot more than they really do. 

I recommend talking to a ranger about their maintenance as it may be more involved than you think.

Understand the fees involved and calculate the total cost for an entire year of management so you can compare the different managers.

@Cody EvansI would say your next play depends on how involved you want to be and what your strategy is.

I had to have it remodeled before it could be rented. 99.999% of the time this method works though. 

., Arms length to avoid a step transaction would involve retail sales which would cause a recognition of gain anyway. 

If you're buying much quicker than that, I fear you might not have had enough time to do enough due diligence.The problem with your current method is that it leaves no room for error and is dependent on everything going right. 

Chris Gordon When analyzing an asset whichever method you use is a forecast as you cannot predict future cash flows or values.

I am not a CPA, so check with yours first, but I believe you are able to file a forms 3115 and 481a (change of method of accounting) which allow you to claim previous year's depreciation without actually amending previous years tax returns.