https://www.biggerpockets.com/filesI have uploaded my own spreadsheet file to my BP Fileplace which has an analyzer and estimator tool if you want to check it out:https://www.biggerpockets.com/files/user/drobertson/file/house-flipping-spreadsheet-6-lite

What is the approximate cost?

You always have the option of walking away.My recommended course of action is that you extend the contract so that you get YOUR OWN hvac guy can get out to take a look.Your hvac guy won't mind the quick and easy job of diagnosis, give him an hour or two of work, have him write up a lightly padded repair estimate and hand that over to the seller and ask for that amount to be credited.

It's a medical office building located in Prosper, TX and here's a breakdown of the key details:Property Details:Sale Type: Investment or Owner UserProperty Type: OfficeProperty Subtype: MedicalBuilding Size: 9,657 SFBuilding Class: BYear Built: 2023Percent Leased: 100% (Currently Fully Occupied)Tenancy: Multiple TenantsBuilding Height: 1 StoryLand Acres: 1.00 ACZoning: CommercialFinancials:Purchase Price: $676,000 + $81,000 Tenant Improvement (TI)Down Payment: 20%Commission: $22,000 (agent commission)Monthly Rent: $5,400 + NNN (exact expenses not specified)Vacancy (First 6 Months): Estimated expense of $27,600 (assuming rent starts after 6 months)Mortgage Payment Options:25 year term - $4,000/month15 year term - $4,600/monthLooking for Your Expertise:Does this fully leased medical office building present a good potential investment opportunity?

I take care of the whole project from initial inquiry, estimate, demo and tile install.

In Riverside you cannot estimate or allocate usage based on square footage or number of occupants on gas or electric, but you can for the water.

Then when you add in realtor fees, etc, if we sold I estimate it to be around a $35k-$50k loss.

We have contractors who can get us estimates for inspection items and we use that to negotiate.A couple more pieces of advice I would like to leave you with:- Make sure your Agent is knowledgeable about rental properties and what it takes to get them rent ready.  

The mortgage will be for approximately 900k at 4.25% and in my name.

It depends on the type of stain but it may be worth getting an estimate to see if it could work in your situation.