Best cheaper liquor to try?

Hiii! My boyfriend recently turned 21 and while we are not strangers to alcohol, we are strangers to good alcohol. What he is thinking is that liquor is the best way to save money when drinking since you drink less of it because it’s stronger so he is interested in trying some new liquors.

He has tried the popular stuff that most 21 year olds have tried, like crown, svedka, smirnoff, kraken, malibu, captain morgans, etc., and would like to try something thats in that similar price range but is better quality.

Any recommendations would be great! I think his price range is preferably lower than $30 which I know limits him quite a bit. Any recommendations that are over $30 are welcome too and will be kept in mind for when he can afford to spend more. Thank you!