Gooood Morning,
I would say that there would definitely be a risk when purchasing from carousell or any other forums of online - meet up purchasing methods.
But there are ways of reducing or mitigating risk such as checking out the seller's ratings and to set a criteria in mind for the product (in this case an SSD) that you are getting - such as it has to be i.e. a sealed and unused with receipt and stick to the criteria and not deviate from it if the criteria is not met.
Also if it's too good to be true, walk away.
Can't really help you out on recommendations, am not really an SSD person so I would let other experienced forumers help you out.
Cheers.