If you
just want plat,
https://wiki.project1999.com/Treasure%20Hunting%20Guide. For XP check out
https://wiki.project1999.com/Per-Level_Hunting_Guide. If you want both, check both, but dig a little.
On the treasure one I think Grobb is your best bet: I even wrote
a guide for it, but the short version is that each guard is blue and drops 10p of loot, and an Enchanter you can then turn around and sell the loot in the same zone.
There's also the classic Ice Giants (who drop coin), and if you don't mind murdering the nice little otter people Cobalt Scar can be good too (they drop gems).
When I plug in 46 Enchanter into the per-level guide I see ... well, Grobb again
[You must be logged in to view images. Log in or Register.] But also both the Mercenary Camp in Eastern Wastes, and outside Karnor's, will probably be good XP with
some plat (though not as much as Grobb, Ice Giants, or CS).