I check county records, tax records, current appraisal from the local municipality, and check for comps in the local are with respect to the properties condition. 

Yes, you are right, there are some buying opportunities given the current market conditions.

They are going to have the most insight as to rents, areas, and the condition of the properties.

This type of loan is getting very tight lately due to market conditions.

Before that, I engaged in the Vero Beach, FL condo market, but opted to sell my properties there due to weather and rising HOA fees.

"real estate rental income will not qualify one for adopting a Solo 401k Plan", You will be providing the service of maintaining property in good condition, doing repairs etc., for the purpose of generating income.

@Mark WalkerCap rates vary by asset class (A, B, C, D), condition, and vintage of the asset and the market, to name a few things. 

Here are some resources you might read for PA.https://www.macdonaldillig.com/judicial-tax-salehttps://www.taxsaleresources.com/state/pennsylvaniahttps://www.legis.state.pa.us/WU01/LI/LI/US/PDF/1947/0/0542....https://www.indianacountypa.gov/departments/tax-claim/proper...https://www.biggerpockets.com/forums/311/topics/122546-aquir...https://www.vinsko.com/blog/2022/08/tax-sales-sheriff-sales-...https://phillysheriff.com/real-estate/conditions-of-sale-for...https://www.curleyrothman.com/blog/how-do-tax-sales-work-in-...https://www.legis.state.pa.us/WU01/LI/LI/US/PDF/1947/0/0542....Here are some resources you might read for MD.https://www.taxsaleresources.com/blog/expert-interview-with-...

The program looks at location, property value, amount owing, interest rate, taxes, insurance, rents, condition, etc and several exit strategies.When we make an offer to buy, we can offer cash, subject to, wrap, seller financing, lease option, seller carryback and so on.Obviously if we wholesale the property, there is no carrying management needed, and if use a lease option to sell, the optionee is responsible for maintenance and repairs.

However they are slow and they will do their research to determine valuesWhoever the taxing authority is, they will look at the value of the property in its current condition, then subtract foreclosure costs, marketing and closing costs to arrive at a net value to them.