Actually, in my experience, I have not found them to be tighter or more generous with money. I've found them to be about the same with handling money as non-Jws
Which is interesting considering jws proudly state they are followers of christ and his disciples who eschewed material possessions and material aspirations. Actually I recall one (haughty) elder telling me that he chose servants and elders who were "successful" in business as in his opinion were better organisers. At that time, every servant and elder on his team were pulling dodgy business pratices. I mean every (including himself). Yes it was a loveless, judicial congregation.
I look back now after years of experience and study an realise that he had obsessive compulsive disorder. At the dinner table he would get incredibly distressed if the siverware wasn't in the correct order and as far as washing hands... Anyhow I digress.