I've never met an ISP that sells Racks in a colo that didn't bill transit at 95th percentile (if you chose to use theirs). Are you hosting bare metal, or is your colo providing the physical server?
If you deal with a Datacenter that is just providing you with a Cage + Power + Cooling + Physical Security, you are almost always going to pay for transit @95th percentile.
If you deal with a Datacenter that is just providing you with a Cage + Power + Cooling + Physical Security, you are almost always going to pay for transit @95th percentile.