I know this is a pretty subjective and has several variables, but I'm kind of in a pinch currently.

I'm either looking to get another set of MR Bils' used-but wanting to know about how long they will last before you need to rebuild them (on average)

Or whether or not I should just bite the bullet and go with something like ST Suspension/Megan coilovers.

 

Just in case you decide to go this route, I have my bils sitting in my basement. My car has 20,000 on it now and I think I removed them when it was at about 10,000 or so.

 

I would go with another per of MR Bilstein's or Bilstein's HD on tire rack, they're quite similar. My 9 originally came with stock mr bilstein's and it was at 80k miles. I am looking for a set myself now to replace.