General question about pvp and hero power

I want to do a lot of pvp but as a minimal spending player, I want to allocate my money and resources as best as possible. I know you have to have a good balance of gear, skills, pvp tech and hero level but is there say a certain order I should follow to get the best bang for my buck?

For example, get my HQ as high as possible but then what? Max out exp first? Max out skills first? Gear first? Pvp tech first? Drone first?