Components like cabinet's, flooring etc., that is never intended to be eternal, it's like socks, there made for use and then to be refreshed at certain intervals. 

I had new kitchen cabinets, quartz countertops, built in microwave, new bathroom vanity installed.

May owners are foreclosed on and decide to steal the appliances, cabinets, doors, flooring, plumbing fixtures, etc.

Im looking for flooring , cabinets , showers ,lights .

updating paint, tile, cabinets, and countertops.

You will want to do installment payments where if the deadlines are met for getting let's say flooring, cabinets, and dry wall done by the 4th week, then they get paid with a little extra bonus. 

Ran into a cabinet shortage during some renovations, so I started a cabinet company and partnered with a manufacturer with 100MIl in inventory to alleviate the cabinet supply issues for myself and my clients.

If you are cool doing floor, cabinets, paint, etc that is pretty easy and manageable.  

If you can paint and install cabinets, trim and other light finish work you could probably do it for a $100 sq/ft.  

For unusual or extreme situations, you would charge the line item price plus your hourly for actual time spent.Individual line items might be window shades, window glass, toilet tank lid, toilet seat, towel rack, door hinge, closet door, outlet/switch, bedroom light, kitchen light, individual bulbs, ceiling fan/light combo, medicine cabinet, repair wall 6", paint touch up per 10' wall, flooring (by type), clogged or slow drain, food disposer, refrigerator bars, drip pans, stove burners, etc.