Tax liens have nothing to do with Private lending.

Yet, I barely survive thanks only to the pandemic era low interest rates and tax abatement.

Several large Georgia State tax breaks were also part of the deal.

So, the desirability of the deal depends on assumed appreciation of the property’s value.

So, I don't think comparable sales of properties that can be built on would be very useful and non-buildable lots are likely to be all over the map depending on a wide range of factors making each of them unsuitable for building.

Some lenders (depending on the number of units) will even require two appraisals..paid whether the loan closes or not.- Reserves.

This is something I'd consider in the future.Out of state investing:- Nevada has low property tax rates. 

Some questions I have: -What is the capital gains tax situation on something like this?

Your local S8 Housing Commission should have an info sheet on their website that shows their deductions if landlord chooses not to include electric, gas & water.Even more critical, your $680 mortgage amount, that you appear to be comparing to the S8 rent, should include ALL the other housing ownership costs: property taxes, insurance, vacancy/tenant nonperformance (S8 tenant may have to pay part of rent), maintenance & miscellaneous.Suggest you use the BP Calculator for this.

Commercial lenders don't usually offer 'pre approvals' but will provide sellers with a letter of intent.