£31 for a 2020A? Not sure where you've seen that.
I'd probably get
this one for £19, which is fulfilled by the jungle people. 3A is better than 2A PSU, but an extra £12 is a bit much for one of these in my opinion, unless it comes with a better 5A PSU; which it doesn't. You'd be better off spending the extra £12 on a 5A PSU separately, if needed.
Anyway, the 2024A one for £26 is the one I was referring to. I was wrong though. I thought it has a better PSU included, but looking through some comments though, when someone asked what amp the PSU was, two people said that they got 2A PSUs.
So, best not to assume something comes with a 5A PSU unless stated.
Just had a look on the famous auction site, just to see if I can spot one with a 5A PSU and I saw someone selling the same 2020A that's on the jungle site for £19, they had for £41! Can buy a SMSL SA36 for that. [insert facepalm gif]