I've heard some shocking things about cot quality - I've had 4 2nd hand over the years and they were great.
I recommend one with a one handed dropside option as they same to be sturdier built and don't rely on those tiny plastic catches that break easily if you lean on the cot side
and one that has a very high top level as it's very very useful when they are tiny to not to have to bother using the dropside thing you can just pop them in without having to lean over too much.
Really you only need 2 levels - high top level and very low bottom level............
Sometimes I think if you buy a cot 2nd hand you can see how sturdy it really is. I'm sure it was a few M&P ones that I've heard being slated - SIL had to bin hers after only 2 children neither of whom every climbed out etc!