13-20 in 2 days (maybe 1) every 2 lvl's after that up to 25 is another day, then 1.5 more lvls per day (this is just about the fastest)
13-20 = 500 fg
every lvl after 20 is 75fg.
after 25 its 150fg per lvl

abyss lvl'ing is annoying, hence price jump.