If my wife was in an auto accident and had $50 k in medical bills, how much should I start for settlement and settle at what range?

There's no simple answer. First, you need to figure out the most you could reasonably get if you went to trial and won. That's typically (more or less) the sum of:

1) Your out-of-pocket, or unreimbursed by insurance, medical bills; you cannot collect compensation for bills paid by your insurer for you.

2) Any property (e.g. car) damage not paid by insurance.

3) Lost wages, if any; and also reduced or diminished future earning potential, if any.

4) Other out of pocket costs (e.g. if a home aide of some kind had to be hired; if you had to do some construction to make your home more handicappped accessible).

5) "Pain and suffering" if the injury caused signficiant disability, disfigurement, or life impairment which last weeks, months or longer. For more borderline cases, this might be equal to 1 times (or less) your medical costs; for serious, significant, or long-lasting conditions, made equal to 2  - 3 times medical.

The sum of the above is approximately the most you'd get. In a settlement, you accept less than that: for you, you take less because by settling, you get the money months or often years afters, and you incur less legal expenses; and the other side settles to pay less. Most settlement probably are in the range of 25% to 50% what you could get at trial; you should start out seeking around 2/3 or 60% or so of what you might get if you went to trial and won (and remember: it's never certain that you'll win anyway) and then see if you can get them to agree to pay an amount you're comfortable with.