I find that depending on the market $300-500/mo are fairly normal and if compared to what you would pay with a single family home on some utilities, maintenance, and management, it's a good deal.

You can find comparable sales in 2017 and use that dollar/acre figure to arrive at the fair market value then. 

The wholesalers in Philly are comparatively decent in my opinion and there are still deals there.

Do you know the comparables in the area?

We intentionally compared them against each other on different properties.

Compared to STRs and LTRs?

Best pay compared to cost of living.

If you compare it with growth from Stock investment you will be disappointed.

This has been well worth it compared to the 40+ hours I was previously spending doing this myself come tax prep time.

Comparing this to oil or timber rights is comparing apples to hand grenades.