I ended up getting the listing as an agent, but only after I exhausted all possibilities of a cash sale to one of my best investors/partners.  

You could whole sale these deals or you could broker them if you have a broker license.

"The man who represents himself has a fool for a client" was said about attorneys, but it could be said about a new investor representing himself in a sales transaction.

They've been advertising their new construction inventory on my Investment Properties For Sale Show since Q4 2024.

Also with a 10 to 15 year lease if they ever decide to leave and sublease the space for a different location then not many years left to be obligated on primary lease term or negotiate for early release and termination.A Wendy's franchisee that owns 50 to 60 units you would need to see if guarantee goes to all the units or they just put 10 of the low sales crappy stores in there.

If this property is hard to rent, or is functionally obsolescent (only 1 bathroom, no yard, etc), or has deferred maintenance that will be costly, or is in a location that is not appealing to Tenants, then maybe a sale would be a good option in favor of a property that has better Tenant appeal, which will likely increase rent and avoid long vacancies in between Tenants.An option to consider....

The debt can derail the deal later on when debt service rises or a call in the market forces a sale at a non-optimal time.

But to answer your question, House canary is good for rent rates, zillow is a good tool for property data and for seeing what is for rent for how much, sales comps etc. 

I have 2 10 Unit Multifamily buildings in Birmingham Al available for sale.

For the residential side, check nearby apartment rents and recent sales of similar mixed-use buildings to get a sense of value.