Anything over £100 is way too much for a 550w psu considering that you can get top quality 650w and 750w psu's in the £97-110 range
Hmm, looking more into this and whilst I found the gold rated EVGA SNG3 650 for £110 (550 for £100) +del, it 'only' has a 7yr warrantee. Vs the Seasonics 10yr for the Focus PX 650's (£130 incl del), or PX 550 (£115 incl del), and they're Platinum rated.
Or the disappearing Seasonic Prime Ultra 550's 12 yrs! (£115 incl. del. also Platinum rated).
But maybe the PX 550s will be cheaper when supply goes back to normal? Well according to Skinflint, earlier this year they were ~£105 (incl. del.), which was their lowest in the past year. Even if they go back to that price, I think the extra £10 for the Ultra 550's 2yr longer warrantee is a fair trade off.
Btw, whilst a Gold rated 550w would save me £16.81/yr, and Platinum 650w £20.93/yr [edit] figures corrected (a 550w Plat slightly more) on electricity bills (vs my old TX650), it seems the latter are worth getting due to my high run times & load (but not the pricey 650w models!).
Unless I've missed some PSUs? (I've checked out EVGA & Superflower, both have shorter warrantees). I think I've covered all options of Plat 550w PSUs with 10+yr warrantees (which their aren't many!).
Good luck, keep me posted. I like camelcamelcamel to give me a better idea on price trends.
I've since found that
Skinflint.co.uk also gives historic prices (upto 1yr) and it isn't limited to Amazon.