Their asking price was negotiable to some extent and was below market but not by the kind of margin a $1000 price would be.

Will they want a detailed project analysis or will pall park figures work if the profit margin is big enough?

And depending on the down payment, monthly payments and the profit margin in the transaction, I might even consider negative amortization.

Do a cost approach analysis to determine your margin.

Sales are up over last year by large margin (30%) and prices have increased by a small margin (4-6%).

When calculating this don't forget that when moving most of these folks can probably find some kind of "1st month free" deal for new tenants so that's why I suggest a 10% margin between your "new" rents and your estimate of market rates.

VERY hard to make a profitable margin on it and VERY likely you'll lose money.

Get enough comps to know it's a good opportunity.Second, figure out what needs to be done to the property to make it appealing, if you're going to flip it, and get an estimate on the work.Third, figure out what your margin of profit is on the deal.

The po will probably still be in business after the next 9-11 and so will trailer parks, but marginal tenants may not?

I agree with All Cash, the margin is very thin and since the market seems to be lukewarm as far as expected appreciation.