> I dunno... maybe the shop will lose its bulk discount rate from a
> supplier if it doen't buy/sell/use enough parts. Never having been a
> buyer for anyone, I can't say for sure. Opinion, Ron?

The shop is using parts as a profit center and simply doesn't want to lose
the extra profit. Simply put, some shops are greedier than others.  It is
not uncommon for a repair shop to mark parts up 50-75 percent, but also they
typically don't buy them at very good prices in the first place; hence their
high parts prices.  I once saw a local shop charge a customer $45 for a
Vanagon tailpipe!  I sell them for about $15.  When he called the shop on
it, the shop proved that they had paid $33 for it to their wholesale
supplier, more than double my *retail* price!  So the shop thought they were
marking up the part by a fairly resonable 25%, but in fact the customer
ended up paying three times what he could have for the same part.  He would
have been better off paying the shop an extra $10 in profit for the repair,
and still buying the part from me!

The shop in question probably will not lose too much business by refusing to
install customer parts, since most customers aren't savy enough to supply
their own parts.  But you're right that paying their prices for parts will
effectively drive up the cost of repairs by a huge margin.  It does sound
like it's time to check out other shops in the area.

- Ron Salmon
 The Bus Depot
 http://www.busdepot.com