[TamDenholm]

Your skills are worth what someone will pay. "How much are you worth?" It depends on how you frame the question. Consider the following scenarios for the same question.

If you make yourself available on oDesk or similiar, your client is looking for a cheap code monkey to do usually, crappy work. You'll maybe get $10-$15 an hour.

If you get yourself a permie job at a small agency in Edinburgh where i'm from, you'll get maybe £28k a year.

If you become a contractor and work in London, you'll command £450 a day.

If you position yourself as a technical business consultant that provides a piece of software that allows an international car manufacturer to sell more cars every year, you'll earn millions.

All of those things can be true for "a rails developer". It depends on a lot of other factors that have nothing to do with programming and are often overlooked by developers.