It is interesting to watch, but you can waste a whole day easily waiting on the representatives to show up and begin doing their thing.  

We live in San Diego California where units are easily  500k-900k for a decent duplex.

A scenario like that could easily cost you $10K+ and untold amount of heartache. 

Or, as long as the inspection checks out, is it something that is easily managed and won't cause a lot of headache in the future?

BP's filtering system is extremely sensitive.

Because as you mentioned, the cost of construction here being what it is, a bare shell could easily take 100K to complete.Do these investors just have good marketing that generates those kind of deals?

. $15 application fee required. that filters out 60% of deadbeats.  

I have 11 what I call A's and they are always full so I have no vacancy factor.. maintenance costs 2 to 3% and that is just filters ... but these homes I brought brand new 5 and 6 years ago.. same cannot be said for used homes generally

After you do it this way, he'll have no basis for a lien, you could get it easily quashed, and he may create some legal issues for himself if he does file a lien.

Typically, if the other party doesn't show up for court, you can easily win by default.