well, if you can invest fg, you can earn some.
for my first climb (solo) i invested around 50fg for very low gear. Every climb there are some items you can sell on the market vs 1fg (look in trade forum for the "muters, glyphers and friendly people"-thread)
Some days ago i also saw a guy who offered 30fg each guild point ( 1 climb = lvl 1-71, then masterquest = 1 or more guildpoints) so yes, you can earn fg.
(with ultra low gear and solo it took me around 1-2 days for 1 climb - you have many breaks to regenerate, so you can do other things while playing)