[thifm]

Keep your job and do interviews for companies in the $75-90k range.

It won't look so bad as much as you think if you leave after fiding another job. You negotiated badly and they ripped you off... also, a >50% raise should always be a reason to leave your current company, it doesn't matter if you are there for a week or a decade.

You are the "prize", start acting like it and they will treat you like so.

[Kerrick]

See, I'm not sure I want a different job. The people and the product are both really cool, I'd rather not leave.