1. Don't buy overpriced Armor/Weapon Drill Great
If you are in rush, buy Armor/Weapon Drill Master for 10k-15k each in Big Beam (Tunnel Master NPC). They are lesser than Great, but its better than normal drill. Trust me they work!
2. Make your own suit
Stop being fooled by merchant. You can make your own suit with green diamonds and Opal A price reduced now. Make it to Legendary and use refresh stone if necessary.
3. There is event that let you have any costume piece
I can not stop -facepalm- seeing costume body in stall for more than 5m while there is Lost Art that let you get literally any costume for 120 pts.
4. Stop buying arrow/bolt/iou
They are junk.
5. Don't buy gold!
You will get banned.
6. Be cautious when pricing in stall.
Because your mouse can fail you.
7. Prepare some Go anywhere or Teleport before raiding.
Because our pill keep running.

(More secret will be revealed later)