It's in a city (outside the USA in Mexico) that has seen major growth the last 3-5 years and has great prospects to continue growing thanks to nearshoring and high cost of living across the border in the USA.I spoke to an architect and it looks like a 4-unit building can be built on there.

If you are looking for a consistent performing STR assets then I would highly recommend Fort Morgan, Gulf Shores, Orange Beach, Perdido Key area along the AL/FL coastI have helped many recent investors find turnkeys properties as well as vacant lots for them to build STR new construction homes on.

We are a group and one division do wholesaling,  we buy from them all the time and Multifamily buildings too.

And then shared that most people don't understand how much work it really takes to build up a portfolio.

These expenditures are capitalized, meaning they are added to the property's basis and depreciated over time.Examples of Capital ExpendituresBuilding Additions: Adding a new room, deck, or other structural improvements.Major Renovations: Remodeling a kitchen or bathroom, replacing the roof, or significant electrical and plumbing upgrades.Appliance Replacement: Installing new HVAC systems, water heaters, or other major appliances.Structural Repairs: Replacing the foundation or significant repairs to the building’s structure.Labor CostsLabor Costs: The costs paid to contractors, electricians, plumbers, carpenters, and other professionals involved in the renovation are part of capital expenditures.Example of Capital Expenditures with LaborSuppose you renovate a rental property, including a new kitchen and bathroom.Materials: $15,000Labor Costs: $10,000Total Capital Expenditure: $25,000This $25,000 would be capitalized and added to the property's basis.

I have decent reserves, but it wouldn't hurt to build them up a little more before considering paying down the mortgage. 

Do we look at the value of the building as a whole?

You could also do some small development like a DADU build + condoization to multiply that tax-free money.

I am trying to figure out how I can find a contractor or inspector that I can trust to view and walkthrough potential investment properties and would give me honest estimates, etc.

You should have  a lot of options if it's a building that's been updated etc.Farmers itself does some weird things with their deductibles and they're very specific what they want right now.Let me know if I can help.