Good idea would be to revise the title so it makes grammatical sense:
as in
Buyin' n Sellin'
Apostrophes (') are used in words either for contractions (could have= could've), possessives (Mark's car) or -- for what you're attempting -- to stand in for omitted letters,
where
Buying = Buyin'
and = 'n' (which also works as 'n or just n, like you have it)
Selling = Sellin'
It's a good title. Just needs to make more sense.