Vett 1ST timer on best cheapest way to replace the entire fuel pump assy

[PalmSprings]

I have an 88 c4 that sat for 10 years bathing the entire FP assy in old gas
I want to replace all the mechanical/electrical components that are attached to the entire steel fuel pump assy . What is the approximate difference in cost by paying the $280 to $350, Ive seen, for the entire unit assembled vs just replacing each of the components that attach to the fuel pump assy .. The only component parts and prices Ive located so far are the fuel pump for $170 from Chevy and at other parts houses/or ebay, are as low as $60 ACdelco and others.
I havent located any of these:1.the float sending unit. 2- 3 wire loom or assy..3- sending unit? There may be 1 or 2 Ive forgotten. I will also need the gasket for the FP steel assy where the filler neck is screwed/bolted down and the rubber drain boot to top it all off

Thanks for any help.

 

[Wayback]

Amazon.com: Impala Bob's 1988 Corvette Gas Sending Unit: Automotive
You can roll over the image to enlarge. The sending unit itself is tack welded to the gas tube/line. So IMHO I dont thing you can replace just the sender.
The boot
Corvette America - Item X2263: 1984 1996 Gas Tank Filler Neck Boot