You were not overcharged. That is the market value exactly because assholes like you stick the system with unpaid bills. You are the reason that number exists.Hm, well according to
this guy (and several other quick sites), an average foot xray should cost <$200. A bag of saline costs ~$1, but for someone to administer it, bump that to $100, if it's a cheap hospital ($600-700 for an even worse one!). Stitches? Maybe another $100. Local anesthetic? Perhaps $2-300.
Overall a total actual cost of less than a thousand. Double that for "reasonable" doctor/nurse labor of 10-30 minutes, and there's a still-overcharged total of maybe $2000. That he was then billed $8000 for.