samurai

Hi, I seek some advise whether it is worth for me to do an MBA or not, based on my circumstances, which I describe below. I am 35years old, have an engineering degree,with over 13years experience as a software developer, i've been working as an independent (freelance) developer for over 10years, making good money.. (>$100k per year) I do like and do well in management, and would like to climb the coporate ladder, which I cannot if I continue in my present career path. I havent attended a school for formal education since 1990, i.e. 13 years. Do you think its worth for me to do an MBA? if so, what sort of school should I choose? Is it worth spending time and money doing an MBA from a not so famous school? I'd appreciate any response Thanks