The difference in price of material may not be that significant. 

I use 3 categories - mileage, meals, materials, and just drop the receipt expenses into each.

If you have good credit and your family members are not marking up material there is a game I used to play with credit cards.First get a credit card that has 0% interest on purchases for 6 months and you purchase the materials on that card.

Assume $5-20K, depending on location, size of property, building materials used, etc. 

***Seeother notes.Down Payment: $0.00Loan Amount: $80,000.00Loan Points: $0.00Loan Fees:Amortized Over: 20 yearsLoan Interest Rate: 5.000%Monthly P&I: $527.96Income1 Unit $1,400.00    2 Unit $950.00Other $0.00Total $2,350.00ExpensesVacancy $70.50 Repairs $47.00CapEx $117.50 Electricity $200.00Water $25.00 Sewage $25.00Garbage $51.00 Insurance $82.00P&I $527.96 Property Taxes $152.92Misc: Fuel oil $275.00Total $1,573.88Buy & Hold Analysis - 08/27/15 04:43:50Financial ProjectionsTotal Initial Equity: $30,600.00Gross Rent Multiplier: 2.84Income-Expense Ratio (2% Rule): 2.87%Typical Cap Rate: 5.00% Debt Coverage Ratio: 2.47%ARV based on Cap Rate: $312,980.0050% Rule Cash Flow EstimatesTotal Monthly Income: $2,350.00x50% for Expenses: $1,175.00Monthly Payment/Interest Payment: $527.96Total Monthly Cash flow using 50% Rule: $647.04House Size (sq. ft) 1500Year Built 1941Year Renovated 2001Units 2Stories 2Property Type Small Multifamily (2-4 Units)County Appraised Value 110600Pool YesHeating YesGarage 1Construction WoodRoofing ShingleFlooring Types Hardwood & CarpetWiring Condition GoodPlumbing Condition GoodSiding Material WoodOther Info: Owner/ buyer will occupy 1 floor unit for 24 months.

Unlikely that siding material will be a factor for a tenant as far as rent amount is concerned.

Remember this. 4) PEX is wonderful, and ProPex I am a fan of5) When buying a REO the amount of deferred maintenance should not be underestimated.6) Sometimes it would cost less to demo out things than repair them- make sure you factor which is more LABOR and material efficient.

Also can someone point to any source material on the site that deals with short sales?

Current Approach/Reasoning:So currently, because I am a student, part time investor, and a newlywed; money is tight for marketing material.

And it's possible that there are even other materials in the waste lines, depending on when it was built.