Wouldn't it be cheaper to look for new drivers? I priced the drivers in my speakers a while ago and they were available at only about 30 bucks each for the woofer and something like 20 for the others, 140 bucks makes my speakers brand new coupled with a cap change.I don't think you can ship a whole pair of speakers for that outside of using greyhound and having them picked up both ways.
Depends on the speaker. If they are old there may not be replacements with the same specs. If they are new, the drivers might be $1K each or more depending on the type. The replacement midrange for an old pair of Polk Audio speakers I have is well over $100, and they are 25 years old. If you have a cheapo pair of speakers that only cost a couple of hundred bucks it might be cheaper to buy new speakers than drivers. You need to weigh the costs each way.