Planet X: https://www.on-one.co.uk/deals/q/deal-null
£10 +£3.95P&P (unless ordering loads more stuff then no P&P)

Seems like a good offer – I’m in.
NB Check wheel size specs when ordering.

I assume they are so cheap as they are too small for most modern wheels. I bought two recently at that price for hauling/storing spare disc-braked CX wheels (so 700C/29″ with a 135mm rear axle and ~30mm tyres) and we can’t fully close the zips, but they are good enough for what we needed.

I have a couple of those bags, I can get 650b wheels and 2.3 tyres inflated in them and 29er with 2.3 deflated, not fully, in them if this helps anyone