Bargain. Pair it with a nice second hand Celeron and your gleaming for no money at all.
How often do you bend your motherboard ?
But that was my point. If you are going for a £100+ CPU you may as well get a cheap B450 mobo and a Ryzen 5. Then it's not a cheap system any longer.
I'd pair it with i5 7500 - they go for around £100 on Ebay. G5400 is a bad choice. 8GB DDR4 Ram has also gone for £30 to £40 in recent Ebay auctions if you don't mind bidding. You can get new for between £50 - £60. I don't think CEX have adjusted their DDR4 prices recently. But yeah all of this depends on your budget.
But if you only have very limited budget then it may not be a bad shout. £27 mobo and grab a G3258 (£22@CEX) and 2x4Gb DDR3 (£10 each@CEX). So £69. If you want to make a system with this £30 mobo of a magnitude improvement the you are looking at a Pentium G5400 (£80?) and 8gb DDR4 (£60). So £100 more. Quite a big jump for a cheap system.