[DanHulton]

There's already a lot of great advice on what to do in the comments, so let me address a specific part of your question and suggest what NOT to do: Do not learn COBOL and do not try to make a play for maintaining legacy code.

It's not that it's a bad career, and frequently the places that still use COBOL are pretty stable and unlikely to do mass layoffs (governments, banks, insurance companies, etc), but it's TERRIBLE for maximizing your income, which is what your question is about.

If they don't have the money to rewrite all that old legacy code in something needlessly new and shiny, they very likely do not have the money to pay high programmer salaries, either! Well, that, or they have a finance-focused hand at the tiller, working to keep costs (and salaries) down. Neither of which is terribly conducive to you making big bucks in the short term. (And yes, ten years is "the short term". You in ten years will agree with me, even if you don't now. =) )