I shared them with my meetup group in San Francisco last Thursday.4plex:SFH:•Helped me understand long-term costs (& more precise costs for props)•& ACTION STEPS TO IMPROVE!!

These are precisely the Vendors who really need the services of an experienced commercial broker, but as Joel also indicated, the amount of work to properly prepare, market and close a 30 unit building is not 5 to 10 times less work than selling a 150 - 300 unit property ... it may even be more ... so the broker's time is better rewarded in the bigger deals.  

It seems that that age is right around when the effects of good/bad management begin to really show - some units are a little ragged, some pretty nice.What I want to learn is how to be precise about capex estimating.

This is precisely why consumer affairs advises citizens to avoid these businesses.

@Derek CarrollThat is precisely what I said in my post.  

I should have been more precise in my earlier post ... you do not want to execute the Agreement of Purchase and Sale until the option has been exercised.

There are many ways to verify accreditation, many of which do not follow the safe harbor definition precisely.  

It would allow you to fill that number in more precisely and they might have some valuable information on tenant quality and turnover for that area. 

More likely is that once the home is abandoned, then the abandoned home procedure for the state takes over and the park owner can eventually take ownership of the home but there are precise steps they must follow.I have a guide called, "So you want to build an RV Park" which covers more details of the benefits of building vs. buying.  

You should have a better idea after seeing the property, and update your estimates based on that.10% vacancy is a reasonable guess, but like the interest rate I would spend some time trying to get something more precise before making an offer.