NL10 online = NL200 live. A winning NL50 reg online is going to be better than like 99% of NL200 live players; he/she may have some issues with tells
and adjusting ranges for a vastly different player pool, but that reg is going to be just vastly superior in terms of experience (pretty normal for a 21-year-old online pro to have played more hands lifetime than a 60-year-old live pro) and in understanding ranges, manipulating ranges, understanding GTO, etc.
Anyway, the issue is not live vs. online; if you're rolled for $1-$2 live I'd say go for it, it'll probably be good for your game and your bankroll. If you start playing $1-$2 online you will get destroyed.
I've actually come up with a theory as to why stories such as yours are so common (probably more than is statistically likely). When someone takes a shot at higher stakes, regs often profile the newcomer as a composite reg without reads. Along with that come certain assumptions; i.e. that you will be properly balanced in certain spots when in fact, you are totally depolarized in most spots. This can end up in a higher-stakes reg paying you off or bluffing when you pretty much always have it whereas a lower-stakes player will just give up.
Anyway, good luck and keep us posted.