I've actually found it extremely difficult to gain a lot of cash by just doing missions. My first character had over 350 kills and did 60 something missions, and he was still poor. He was lucky to have more than a few 100k's. I would see having over 10mil as being somewhat wealthy, but then again that's pushing it. I would just look at credits as a mainly OOC deal and only IC when another ICly asks. My BHG|Core character walks around in dirt, some leather jacket and rags, and if you ask him about money, he'd probably just laugh. I think I still left a mil or two on him, but it's not really IC as much as it's just OOC money to spot for regens and nanobots.