Definitely aim for a 8 attack MoN. If you form your own squad/join for MoN you won’t have to spend very much money. In terms of attack gear, I would upgrade cape/gloves since those are cheaper than shoes. Weapons are kinda hit or miss. Decent and perfect are easiest to find, the in between are rarer. MW20 should be your last investment as it’s not 100% pass rate.