Advice on 2nd hand 12v fridges/coolboxes

[Welsh will]

Conversion going well at the moment, but now reached a stage where i need to look for something to fit into my fridge cuboard on my Vw T5.
Iv seen lots of nice new fridges but unfortunatly at this present time beyond my budget .
Im now looking for a 12v alternative, lots of 2nd hand units about but was looking for advice on what to look for when purchasing a 2nd hand unit?
Any advice be greatly received as always

 

[Greengrass]

Waeco

I have a waeco compressor fridge for my money there the best, I know there not cheap but there worth that bit more and not a big drain on the batteries either