Have you tried to taper yet? It can be very hard to do so but if you can, it can help so much. I have tapered in the past from a huge amount of norcos and I felt little to no withdrawals. There are also other things that can help such as clonodine. You do need a prescription for that though. Make sure you stick around this forum. You will get so much support and no one here will judge, just help.
How many are you taking a day and what mg?
I can only speak of my rehab, but it was a 6 week outpatient facility and the cost was about 7 grand. Best money I've ever spent. Inpatient rehabs are much more expensive, naturally.