I'll be honest with a budget up to £70 and based on current UK prices on PCPP, I'd consider:
PCPartPicker Part List
Power Supply: Corsair TXM Gold 550 W 80+ Gold Certified Semi-modular ATX Power Supply (£69.98 @ Amazon UK)
Total: £69.98
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2020-10-03 23:35 BST+0100
Reason being is the extra 100W will handle future upgrades, and the TXM is excellent and comes with a 7 year warranty. The VS for example is only 3 years, the BQ-SP I believe is also only 3 years. So the value is significantly better.
The Cooler Master MWE Bronze V2 is only £50 currently but does have a coil whine issue. And the System power 9 is probably good value considering (based on the price I just saw), just not the same quality or warranty as the TXM above. The TXM is much better value in the long run and is also excellent.