That seems high to me just to work on aging, I'm not sure I would tag that as a "consulting" fee. I usually contract my consulting for things like compliance, policies/procedures, fee negotiations, etc. For such things as working aged accounts I tend to go more with about 1/4 of the consulting rate, for your case $30-$40 an hour would be more in line to an average, but I really can't pin point it closer for you w/out really seeing the accounts and work involved. I've taken on aged accounts where much of it was submitting claims never submitted and then I've done ones where the staff never followed up on patient balances. Oh, when I quote a fee for things like this, I never tell them the "hourly" rate. I come up with a flat monthly rate (based on my hourly rate, minus expenses). I do this because the hourly rate usually scares them away because they automatically are not looking at the big picture (no insurance, no time off, no overhead, etc)
I do the same thing for my FPM clients. If I am asked (normally, I'm not) I will tell them the fee is calculated taking into account my time, expenses, etc. I never go into the "hourly rate". No reason to.