I brought cleaning supplies, boxes and bags to them on Wed and said I would be back that Fri. 

In Madison, WI the low inventory has pushed prices up a lot all over though, so people do seem to be making decent spreads on lower end flips (getting sale prices higher than I would have thought in the current market, but that could also get a bit more even on supply/demand at some point, maybe spurred some by rising rates and lessen some of those returns).

No, get a smoking hot deal, then contact these people and say I saw that you were actively flipping homes and I may have a good lead for you.

There are really only two reasons why people are on the internet:1 - To get information (get answers to your questions)2 - To make a decision (like buying something) to with that information.If you can supply both...?

I also get a lot of old off-market plumbing supplies there for repairs and also window and door screens.

here's why:  in a seller's market with, for instance, under 3 months' supply/inventory your normal seller is going to see properties being sold for full retail prices within very short periods of time.  

I also use their braided supply lines with the same leak detection for the dishwasher & fridge water supply lines. 

quantites of material need to be defined. define if you will supply them or will the contractor. ask questions when you dont understand.

Wrongful Eviction, libel/slander, fire if the smoke detectors are not working, water/sewer back ups, etc...

There has been a requirement that a disclosure be supplied by sellers and landlords, but this is a HUD rule that has been around for a while now.