E36 ('93 325is): starter dying? how long?

Howdy folks,

I have a '93 325is with 157k on it, the last 25k of which are mine. Come July,
I have a 1,700-mile road trip planned, and I am concerned about a noise the
car has been making recently:

On turning the key, but before the engine turns over, there is an extra
"rough" noise on top of the usual starter sound (not metal on metal). And
once the starter disengages, a clicking sound that repeats for a couple
seconds, then dies away. The engine starts every time.

OK, so the starter (possibly original?) is dying, I am resigned to that. What
are your experiences? Any guesses on how long it might linger? Cuz BMW-
certified mechanics are a little thin on the ground in the middle of Nebraska.


Thanks,
Matt