OC1 is ~51mbps
OC3 is ~155mbps
OC12 is ~ 620mbps
OC48 is ~ 2.5gpbs
Because this is fibre that must be provisioned to your premises the cost is variable for installation and is going to be hella expensive.
Monthly fees start at something like 7,000-10,000/m (OC3 us closer to 15,000-20,000)