Respuesta :
'Least expensive' has a negative connotation.
Explanation:
The paragraph calls the product's performance as average and then says that the product is least expensive, by association itself it conveys a negative connotation.
However, the phrase can be taken to mean that it is expensive, it is just just the least expensive out of other options available which is a back handed complement.
Finally still, it can mean that the quality of the product is suspect and hence it is priced lower than the other ones. All of these give away a negative connotation.