I always like to look at several years worth of property taxes.

Is taxes going to be higher today or higher in the future? 

Their taxes and insurance may have doubled and they can't afford the house any more.I think geographic is tough because there just isn't typically the turnover any more in most areas. 

Given today's market.But conservatively, at those prices ($1,100 studio, $2,100 house) they would bring in$38,400 a year. 53% of that would go to fixed expenses ($899 mortgage @ 2.15% interest, $5.8k property tax, $4k house insurance).

Besides lists from the tax assessor, how are you finding your deals?  

@Bradley Buxton makes a very good point to make sure to do your due diligence as you won't be an owner occupant like your in-laws.Last bit of advice: Because this is a friendly deal, you want to take your time to make sure you structure it in a way that maximizes tax and cashflow benefits for both parties. 

Rules vary significantly, and you need to be aware of licensing, taxes, and any restrictions.Local Market: Analyze the STR market in your target area.

.- 1031 exchange opportunity: I could potentially do a 1031 exchange to acquire a duplex or triplex, deferring taxes.- Access to funds: I could consider a cash-out refinance or a HELOC to access funds for additional investments.- which property would you recommended me to keep? 

Prices will certainly vary between different tax firms.

But it became too hard of work and too much risk to be making just $30,000-$50,000 per flip (before tax).