If youre to add gear to strict purchase list, such as diamond currency being used. Please leave it as mainly different skinned gear or still lower grade than the best. Pay2win may help developers, but may not be so much fun for some players.
Depending play style of each person; lone wolfs, builders, raiders, etc. Depends where our funds go.
I hope ZR4 will be a bit more equal and complex with raiders vs builders, maybe more of a danger when it comes to zombies also, for both sides.