Is Blademaster the best for solo grind?!

Reaperlocke - Lost City

the build should be
str3,dex1,vit1 on even levels
str3,dex2 on odd levels

LuneLain - Lost City

How i see it is that there are two types of grinding; 1 the xp grinding and 2 the cost effective grinding aka coin farming.

Options for xp grinding are simple, solo axe aoe grinding with or without aid from other class(es). Keep in mind that it's expensive as in that you will spent more coins then that you'll probably gain. Then again the purpose is xp and not making profit.

Options for coin farming are also simple, that's using fists as BM. You can actually farm on magic mobs, preferably on the ones that cast poison. That's because your opener will be shadowless kick lvl 1, which has low mp cost. Ontop of that you can use your physical marrow to even reduce the physical damage taken. You need to keep in mind that the magic mobs will cast their magic/poison a second time during the attack. To avoid that damage throw in your stun, i personally use roar stun. Which also has relatively low mp cost. When it comes to HP recovery i simply use 2spark since it has no cost other than chi which is basically for free and you can spam it since you're fist user. If you fist grind like that you can actually kill 10-15 magic mobs in a row without touching a HP/MP pot. Ontop of that you can speed the process of killing up by using the HP/MP recovery powders. And the cost of those are just low.
And to actually get the most out of DQ drops, don't grind on mobs that are 3 or more lvls higher than you, and don't grind on mobs that are 4 or more lvls below you. Why? 'cause when you grind on mobs within that lvl range you will get the most out of droprate AND XP+ Spirit. When you're outside that lvl range the stats for droprate and xp+spirit do change therefor making it unbalanced.