I thought about both being synonym but the way they are used sounds different even though they mean the same.

" I am looking for cheap stuff" vs " I am looking for the least expensive stuff"

I think it shows the different attitude of a person.

I don't think its the matter of poor or a well to do person. 

Humans are curious animals, we never gonna run out of questions.

I totally agree with you about poor and rich even though it does not apply to all but most.

Nice perspective