I've been considering adding to the storage in my home PC but have a number of smaller HDDs leaving no room to add a new disk (1 SSD, 4 HDD and a DVD-ROM takes up the 6 SATA ports).
I have 2x320GB and 2x160GB = 960GB
CeX will buy the 320GB for £15 each and the 160GB for £10 each.
I can then use the £50 to get a 1.5TB drive on one of the many ~£50 deals popping up.
I imagine plenty of people will be in a similar situation. Sell a bunch of smaller disks and it may pay for an upgrade by itself.
CeX Buying prices for SATA disks to 1TB
1 TB - £25
750GB - £22
640GB - £20
500GB - £17
400GB - £16
320GB - £15
300GB - £14
250GB - £12
200GB - £11
160GB - £10
120GB - £9
80GB - £3