Save your RAW files on DVD-R and keep your Tiff/Jpgs on HD.
Clean out what you do not need. I bets that loads of you (including me) have tons of files that we will NEVER use. No point in keeping them is there.
Then do NOT buy HDD at those Rip-Off prices.
I'll never understand all those that moan about prices then go and pay that price. You/they, deserve to get ripped off.
Same with vehicle fuel. Leave vehicles home for a week and you'll soon find the prices will drop. That means we all do it at same time.
Alas--No one listens. That is why we live in Rip Off Britain.
Waste your cash at your perill..
Be Good.