To be clear, this isn't a "prebuilt" from a system integrator, but just a system someone else has configured?
The 550W PSU is a bit on the low side, IMO. I run an 8086K and 2070S from a quality 550W unit, but only because I upgraded the GPU with the 550W in place - I wouldn't purposely put something together with those components and
only 550W.
For the
actual components included, I think it's a fairly reasonable price.
The specific components would set you back ~ £1500, approx and being relatively new, probably commands more than ~75% of the retail price in most markets (so £1200ish)
That only matters if you wanted those specific component though.
If this was a gaming system (for example), you'd net comparable performance from a 3600 with the stock cooler, B450 board, 16GB and a 2070Super.
Example:
PCPartPicker Part List
CPU: AMD Ryzen 5 3600 3.6 GHz 6-Core Processor (£151.50 @ Amazon UK)
Motherboard: MSI B450 TOMAHAWK MAX ATX AM4 Motherboard (£103.99 @ AWD-IT)
Memory: Team T-FORCE VULCAN TUF Gaming Allian 16 GB (2 x 8 GB) DDR4-3600 Memory (£81.67 @ More Computers)
Storage: Crucial BX500 960 GB 2.5" Solid State Drive (£90.42 @ CCL Computers)
Storage: Seagate Barracuda Compute 2 TB 3.5" 7200RPM Internal Hard Drive (£50.99 @ Box Limited)
Video Card: Inno3D GeForce RTX 2070 SUPER 8 GB Twin X2 OC Video Card (£462.95 @ Overclockers.co.uk)
Case: EVGA DG-75 ATX Mid Tower Case (£48.78 @ Ebuyer)
Power Supply: Corsair TXM Gold 650 W 80+ Gold Certified Semi-modular ATX Power Supply (£79.98 @ Amazon UK)
Total: £1070.28
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2020-03-18 19:29 GMT+0000
As far as warranties are concerned, your mileage will vary component to component. Most manufacturers will require proof of purchase... others you can register components on their website & don't (strictly) need proof of purchase, although still recommended. For the most part, if a CPU or RAM "works", it's not going to fail on you. Biggest concern would be the GPU.
If you wanted the exact configuration offered, I'd think £1200 +/- would be a fair price for it - the lower the better, of course.
If you just want something of similar performance, I don't think it's a particularly good buy.