I would like to read others' take on this question. In my opinion, sentence 2 is the best version.
(1) Ramesh has more money than Suresh. Almost every reader knows its intended meaning, but we can argue for its ambiguity. It might mean two things:
a. Remesh has more money. Suresh has less money in comparison.
b. Remesh has more money. But he has less Suresh. (Maybe Suresh is a unit / name for some precious stone that can be readily liquidated into money.)
(2) Ramesh has more money than Suresh does. This version is super clear that we are comparing money possessed by Ramesh vs. that by Suresh.
(3) Ramesh has more money than Suresh has. To me, it is just as clear as (2), but "does" in (2) sounds better than "has" in (3).
Look forward to hearing other's opinions!