Gerry is probably the best to answer this because he's got more experience/connections with uc300eth. However for me the things to look for are one that can use 24v for inputs and is powered by 24V not 5v or from USB. Unfortunately don't think £50 is going to buy one that will have these features.!

Personaly I will only use Cslabs controllers on machines I build so don't have this problem and rarely buy Bob's these days. If I was it would probably come from PMDX in the states as they are the only BOB I've used and not had issues with.