I'm not saying that the price range system is all bad. But, to say that you cannot narrow in on a range based on details provided does seem like a bait and switch tactic used by many...not all, but many.
I get calls from people all the time stating that their tech says that their heads are toast and need to be replaced. In such cases I tell the client that if the tech's diagnosis is correct, the price will likely be our major recovery rate. But, it is not uncommon for a tech to misdiagnose the drive and it might just be a minor recovery.
Back in the day when we did quote based on each case, we still had a unofficial ranges, based on different issues, for example:
Logical - $300 - $600
Firmware / Electronics - $500 - $900
Heads / Spindle - $750 - $1500
Slim Chance - $1500 - $5000
It doesn't seem to hard to tell a client, "based on your description, the price would probably fall within this range, but until we assess it, there are no guarantees."
It is all in the approach.