Am considering getting some new cabinetry for the kitchen this year. To
begin some research I stopped by Home Depot for ideas.

They offer installation as an option should you not have a contractor.
So I asked a very general question: "is there a rule of thumb regarding
the labor to install the cabinets?" The designer woman said that would
be double the price of the cabinets.

So if I pick $3,000 cabinets I figure on $6,000 to have them installed.
And $5,000 cabinets would cost $10,000. All for say the same 10ft wall.
Why should $5,000 cabinets be $4,000 more expensive to install?

Dilemma is I was intending to do much of the prep work myself. Items
like removing old cabinetry, replacing sheetrock, painting, etc. So how
should I approach HD, Lowes, or any other contractor for true bids on
simply installing the stuff?

Being that I'm just getting started I haven't ruled out having the
entire job done. At this point I need to determine the value advantage
of various options.