bribes can I guess go up to about 200k, most I payed was 150k, maybe thats the max aswell, but spending in end game much on bribes is anyway stupid, for the amount you get bonus for one faction, your faction status will go down for those that are enemys of them, so bribes are only good to balance your faction status faster, or if you really want to go to some station that is atm hostile to you. (like my little one for those corsairs, cause I wantet to visit crete and tripoli, damn intersting stuff in the news, I could bet that this stuff will be in the expansion)
and ships well, once you have the first million, and your ship, you never ever really need money, just kill something if you like, tractor the cargo, sell it somewhere, you can do this on your way. while exploring, you will aswell tractor in a good amount of weapon, which can alone make easly 100k profit, add anout 50-100k for the cargo, and that was just one 10 minutes trip to the next system
once your in high end gameplay, there is not much content left, not much to do with your money, and getting into the high end area is damn easy aswell with just some hours of (borning cause repitiv) trading.
What I really personaly enjoy atm is getting mates to omicron theta, its damn fun, to take a route in hostile space with some lowbie and break with him to theta thru.
you have there really to be fast, kill the enemys, give him cover, get your ship between the enemy and him, taking shots, direkt him, look in battle at the map to tell him where to next, and, and, and
great fun, though it takes that way just about 2 hours till someone from level 1 is maxed out. with all weapons, best ship, and at at least crete or malta. (even shorter if he decide that he wants a sabre, cause it so easy to access)