a better way is to get to lvl30 and mastery lvl to 30 with 0 gap but only keep skills at lvl21, get cursed hearts and delvl mastery back to 21 and start farming in a party
you can have a full 3rd degree armour set, use lvl30 houses (really usefull while getting out of town with the fast chickens), and use lvl20 skills,
while in a party of lvl30s, you should be getting 5k SP in 3 hours easily or 10k SP with gold tickets