If you will be purchasing materials those cards offer some discounts and in addition you can get pro discounted pricing on larger orders as well.

3- what is the cost of materials?

I actually have two options for this property: 1) Rent out the existing 25 storage units AND rent out the building plus add the 25 additional units out of pocket.OR 2) Rent out the existing 25 storage units and added the 25 additional units out of pocket to rent them out BUT keep the metal building for my GC business to where we have offices and storage for building materials.

I have a lot of extra materials from the first renovation.

But you will want to change the code for access right away as fired contractors can come back and take materials from you for other jobs.

Shortages of construction labor and material will also have a major impact upon pricing. 

Also what brand, material and carpet type should I get?   

Sure, there were a few hiccups along the way (like when a shipment of materials got delayed), but with some late-night calls and a bit of creativity, he turned it around.On the flip side, turnkey properties offer immediate cash flow with less day-to-day hassle.

Please work this material through your professionals and seek the proper advice. 

Taking the time to plan and invest in quality materials or professional help usually pays off with fewer repairs and greater peace of mind.