Insights on cap rates for apartment building in 44313? I know there are variables. In analysis of subject propert the cap rate for 103 property in this area is 5.4%. Requesting investors insight in this market.  Thank...

For example, say I have a foreclosure, or expired listing lead that I would like to find accurate phone numbers for for prospecting.

One workaround could be keeping a separate spreadsheet to track your adjusted tax basis accurately and only using Stessa for operational insights.You could also reach out to a cpa and see if they have a specific recommendation for software to use.  

Quote from @Dave Schimmels: What is a good way to get accurate rent comps with existing tenants based on the area?

Secondly, does anyone know of a good service for accurate revenue estimates for rentals in Costa Rica?

Based on your question, I'm assuming you're looking to flip this property rather than rent it out, is that accurate?

It should be pretty accurate - high level data sites are not always going to be perfect, but should always be directionally correct and AirDNA has a pretty strong track record. 

Could someone let me know if this is accurate or not?

Is my accountant accurate in stating I cannot deduct the expenses related to the property if it's not listed in an LLC?

Besides putting together the best SOW using accurate/actual quotes as @Peter Mckernan and @Alan Asriants commented above, another key aspect is tracking expenses (bookkeeping) and monitoring the budget throughout the project.