I bought all my material at Lowe’s, I found all the coupons I can find, and then some, I made sure I picked a perfect contractor this time as the prior contractor in a prior home  literally stole $12,000 in cash from me.  

there are better coupons online.

The reason this is true is because when you prepay your mortgage, your effectively achieving a rate of return equal to the coupon rate, or loan rate.

Another friend offered his 30% OFF discount voucher for Lowes & 15% OFF coupon HomeDepot (some kind of employee rewards of the month at his company).

Not in vegas, but i bought my wood look tile from Lowes. and i used several 20% off coupons for all supplies, dividing them into several $100 purchases.

I've looked at them since for appliance sets for my rentals but always found much cheaper locally - Appliance Direct scratch and dents (negotiated down) and Lowe's using discount gift cards and coupons with sales.

You couldn't require her to use that company most likely, but if you suggest them, especially with a printed coupon flyer, she will likely use them.

So far I've downloaded my free gifts that came with the coupon code and started listening to the audio book.

Bidding, prefer customer discounts, coupons. 

I have a coupon code for it if needed but I set it up like a multifamily where each room was a unit and they had a designated amount.