Some fairly well known was Geos, in Crystal Caverns 40 group to 55 maybe on soloing, dulak harbor 40 group to 55 maybe on soloing, HGs in Rathe mntns 30 group to 50 maybe solo, Ice Giants in everfrost 40 group 55 solo.
Depends on your experience some of these you might be able to get earlier and some of them you can stay in as most of what they are dropping is coin and you are saying you care more about cash then experience.
As to lower levels, Wisp island like 10-15, Sol A 20group to 35ish solo. Ldons decent from like 20 on with exp and stuff you can get from rewards.
Of course there are hundreds of places you just need to know what you are looking for hell even spiderling silk can make you good coin.
Some places you are gambling on good drops but often these drops will be greater when sold then all the coin splits.
I would also suggest you look under links here on this board, choose your class and go to message boards for it often you will find that these sites have great walkthroughs on what to do where and when.