The $5k to $10k difference is basically your GC's overhead and profit to manage the project and make it worth their time.Here's what I would expect to pay if I managed it myself:KitchenCabinets Material: ~$4k or lessCabinet Install: ~$1kGranite Countertops: $1.5 to $2kSink & Kitchen Faucet, Disposal, DW & Ref Hookup $500Appliances $2kFlooring (200 sf x $6/sf) = $1,200Electrical/Lighting = $500? 

We then have to store it for 30 days then can dispose of it.

The logic is that if you are in financial distress you are much more likly to walk away from your investment property than from your home, so they have  abigger risk and then have to dispose the property with a discount.

Tomcat makes a disposable bait station that kids and animals supposedly can't get into, I don't trust those.

Some have asbestos and other items that make tearing them down and disposal for haul away more expensive.

He charged me $2k to purchase and install a 75 gal gas water heater, and dispose of the old.

Auto shops are notorious for disposing of stuff on site so if you ever sell the property and don't have a clean Phase 1 you can be held liable for ever!  

I have about 80k of disposable income.

Such as if a garbage disposal fails, replace with a garbage disposal.

At that point it becomes scale to make those types of properties work you need the ability to buy a lot of them to get any real appreciable income that is disposable..