Materials and labor cost the same, regardless of how much rent you charge.

Annual numbers:Cash down: just under $52,000 (down payment, CC, materials + labor)Gross rent: $20,535 (5% vacancy which is very high but had to include due to the delay in carpet install.Expenses: $14,817 (Mortgage, taxes, insurance, maint. fees)$476.50/month before reservesMy experience with rentals where I pay a maintenance fee so far (no roof, no hvac): <<$50/year additional expenses, but I will set aside $1200/year for fun.$376.50/month after reservesI couldn't have done it with the generous guidance both on BP as well as the awesome veteran investors especially @Michael Mazzella @Bob Bowling :)Yes I do have a mortgage for this one.

- How are surplus materials handled?

My contractor who installed the driveway had extra material leftover from the main portion of the driveway.  

Sam Freshman's book is good background material.  

does anyone know of places in the Denver Area where I can find discounted materials for General Contractors? 

The contractors you want don't have very professional advertising, but they all have to come to the watering hole in the morning and pick up their materials for the day.

You can make design selections, deliver materials as needed, construction cleaning, complete checklists for subs work, and provide specialized contracting services not to exceed $x dollars.  

To add onto Matthew Paul's comment, you have mixed material, they are exposed and not insulated.Different materials expand and contract at different rates.  

The information I’ve learned was priceless in knowing what types of materials to use and knowing how not to over-renovate for a rental versus a home we would be building for ourselves.