Just a thought, instead of paying 15k upfront, is it not better to buy materials directly online and ask the contractor to take delivery of the same and we pay only for the labor and services portion? 

Most of your serious contractors wont pay the extra for Lowes and HD delivery.

If the Commitment and Exception Documents are not delivered to Buyer within the specified time, the time for delivery will be automatically extended up to 15 days or 3 days before the Closing Date, whichever is earlier.

The safe harbor applies to amounts paid during the tax year to acquire or produce what the regs call a “unit of property” (UOP), you must meet these requirements: (1) at the beginning of the tax year, the taxpayer has written accounting procedures treating as an expense for non-tax purposes amounts paid for property costing less than a specified dollar amount (which will be 2500 for you), or with an economic useful life of 12 months or less;.(2) the taxpayer treats the amount paid for the property as an expense on its books and records in accordance with its accounting procedures. ( do this on your bookkeeping software or whatever you utilize)(3) the amount paid for the UOP doesn't exceed $2,500. as substantiated by invoice.Note: The cost for the Unit of Property includes additional costs (for example, delivery fees, installation services, or similar costs) if these additional costs are included on the same invoice with the tangible property.Eg:A purchases 100 printers at $500 each for a total cost of $500,000 as indicated by the invoice.

However you plan to handle it - just be prepared.Number two complaint is delivery by the promised deadlines.

While I agree with your points, your delivery could use some work.

Anywhere you go for purchase they give you receipt but no one ask owner to sign and personally delivery to them.

Waiting for the delivery of my package which should be here by the 8th.

Uber, Lyft, Pizza delivery, cut grass, and any other part time job to save for your first down payment.

Stick w B class neighborhoods or even C+ class and once you have experience then you might consider low end homes.Don’t ignore your dads opinion, yes he can do a better job on his delivery but nobody is perfect..I would start conversation Dad I want to invest in Real Estate, how do you recommend I should start ?