I generally see 2-3x medical bills. Unless the chiro runs up 10k for a sprain. If you are under care for longer than 6 weeks you better have some decent diagnostics to substantiate the need for that care (MRI/CT NCV/EMG etc.). The largest PI bill I have ever had was 11k but we had multiple levels of disc involvement in the cervical and lumbar. They also had several complicating factors that extend the need for care beyond 6 weeks.
If the at fault is Allstate insured all bets are off. You will not get enough to pay your medical unless you go to trial. Even then most of the time juries are conservative in the settlements that are handed out. The last case I testified in, the lady had 12k in medical including me, Physical Medicine Rehab Dr. MRI's, Pain management. The verdict was in her favor for a whopping 4K. Luckily the doctors forgave the debts because we knew she got robbed. On top of that, 3 of the jurors were patients of mine.