I think it all depends on the client base that you are after. If your client base has a huge budget, then I would imagine your gear list and tools would be in the upper $$ ranges. I have also heard some big budget artists mastered material done on semi-pro gear which sounds pretty good to me. I have also heard some big budgets artist's masters done on hight price gear that sounds like shit.
A good room, decent monitors, and a good ear usually yields pretty decent results. The work that I do I like to call it Semi-Pro Processing. It works pretty good for local radio,club,daily listening. My clients never really complain, but to be honest most of them cant really hear what I may be lacking in gear or skills. I also tend to do a better job with certain genres than others. When I get a client with a genre that Im not too familiar with, I bring in another set of ears for processing.
To make my job easier, If I get a mix thats just all wacked up I will ask a client if it could be remixed and what changes to probably make. The better the mix the easier the processing process will be. If a client is looking for sound that I know I cant give them, I recommend someone with better gear and more experience.
Every track may require a different tool, tools, chain, etc. I do stay away from the all in one boxes/plugs. Listen to every track all the way through, then start with a chain that may work for it.
Malcolm