(Holding costs and selling costs would come out of the net profit)Price ranges would be around 200-300k is pretty average for my market.

Not sure what the rents are like around there/what range of people are looking for regular long term rentals in that area.   

I would strongly encourage anyone reading this post who has used that site as guidance in the past to do the same.My normal practice when determining market rent is to use a range of factors, that include GoSection8 data, the local housing authority's published rent matrix, information from Rentometer, from Zillow's rent estimator, and the MLS.

You can use Realtors directly as well, but the expense will likely be in the same range.

That is possible in your price range but it might be further out than you want. 

Need to go conventional with MANUFACTURED home (double wide after 1976) The county or city may restrict the type of foundation: pier, auger, blocks, concrete BUT it must be permanent.

Additionally, I would say realistic ARV would be in the 150k range.

I'm working with some JV partners now to try to find something in the 10-30 unit range.

If you sold, you could look into doing a 1031 exchange to defer the capital gains, and use the ~$450K proceeds as a down payment on a MFH in the $1.5 - $1.8M range which at a decent CAP rate would bring you much better returns than what you're getting now. 

Within our price range.