Thanks to a handy tip:
I was able to learn how to Solo Onyxia!! While this fearesome creature used to require 30-40 60's to take down, she can now be bested by only a few number of courageous heroes. The fight is actually not that difficult... it is just long as she has over a million hit points. The big concern was phase 2, where she flies in the air and whelps come out. I wiped on the first attempt, but I got the hang of it, and on 2nd try I got her down in about 30-45 min. I'm not sure what other classes are capable of soloing, besides druid and maybe a lock. I know people have done it at lvl 70, but those were crazy 3 hour attempts.
She had quite the treasure for me as well, netting 159g, several epics, and an 18 slot bag. I prob won’t do this by myself again anytime soon, as 1 or two dps would speed things up greatly, and would still be making a good amount of gold.