Generally, it is a waste of money to buy a type rating unless you already have a firm job offer in hand which requires that type. The two possible exceptions:
You may benefit from a 737 type if you really want to work at SWA and already meet their mins (however plenty of people are getting the interview without the type these days).
If you have aspirations to be a career corporate pilot, a Citation type rating might be worth the investment (if you don't have any other jet types).
Other than that, buying types is a rich man's hobby.