OK, lets take Broken Water and Halatali.... with an 8 person party

Thats 6 leves.... but because everyone doesn't have the same leves offered, you'll generally end up doing all 9 broken water leves and all 9 Halatali leves....
So thats 18 leves
If you're lucky you can do "Dunesfolk For Dinner" at Broken Water more than once, as that is the most SP gotten from a leve, from my experience....
we've generally seen 50k in SP from Broken Water and 10-15k.. maybe 20k if you're lucky from Halatali.....
thats if all 8 people are within 5 ranks so each person is getting party bonus from everyone else.....

So from 50-60k SP on an ok nite, to about 80k in SP on a GREAT nite doing both camps.....
and thats only 6 leves...
You'd still have 2 more leve spots to go do like Iron Lake or something (Great Hoary Toads is a good one)
the top 2 ranks (48 to 49 and 49 to 50) are 100k in SP per rank
but the ranks through the 30's are way less.... So on average, doing just leves every day with a full group and a ton of links, less than a month from 1 to 50...
Doing the leves solo though... wow... that would take a while longer... quite a bit longer actually...