We had an IBM XT given to us back in the late 1980’s. I remember upgrading the original 10MB HD to a GIANT Seagate 32 MB for “only” $279.
That’s over $485 in today’s dollars.
I used to work at Computerland in the 80’s and would setup new computers.
AST Above boards were the memory board of choice then. 256K chips with 9 chips in a bank (8 data and 1 parity bits) and 4 banks to make one MB. The chips cost $50 each.
$50/chip
9 chips/bank
4banks / MB
2 MB/board
optional daughter board would hold 2 more MB.
Total over $7,000 for 4 MB of memory.