I would keep that low interest rate and the cash flow as a nice cushion to enjoy when times get rough.

A low-cost investment in fencing or a gravel driveway could make the land attractive for outdoor storage.Recreational Use: Open the land for recreational activities like ATV riding, horseback riding, or camping.

That's useful for informing decisions.With respect to the interest rate: I do have a sense that borrowing at such a low rate can be viewed as an asset.

Holding onto your home as a rental could be wise, given your low mortgage, strong equity, and rental income potential.

My guess is that LTV would be low and the rate would be higher.

If we sell it inside a year (short-term), his regular tax rate is still low because he has no regular income. 

Low 7s is probably the right range right now, however we are still funding a good amount in the sixes range right now as well.Many thanks for any insights & guidance.Tim 

Is it solely related to flippers wanting to keep costs low? 

This is a low-risk way to learn about property management, tenant screening, maintenance, and more.

Plus you get interest income on top of your principal payments, too.Also allows you to spread the taxable gain out over time, which would help you keep taxable income low and potentially still contribute to Roth IRA in the year that you sell.