That's not how core charges work: you are charged on shipment for the $39 rebuilt caliper and a $30 core charge, totalling $69. When you return the used caliper, they refund you the core charge, netting to $39.
--
See the 700/900 FAQ under 'Select Link' button on the top right.

It's still a good price. You got the ones without the pads and hardware installed. I just ordered a set with pads and new hardware, which came out to $55 each not incl. core charge. You will be amazed at how fast Groton ships your parts to you - they're probably outside your front door right now!

As I posted before:

Of course, it should have been obvious to me.
Anything that sounds too good to be true...
I fool so feelish. Thanks.
--
-Cool Volvo- 1982 240 4 Spd OD w/ 238K, 1989 240 5 Spd w/ 227K. Past proud owner of 1966 122, 1968 144, 1970 145, 1972 144, 1980 245

Others replied to the core charge aspect. As to the calipers, I bought a set with no problems after about 2 years of use.

I've found it best to always ask about the core return policy of an unfamiliar vendor. Sometimes there is a time limit. Some require your core item immediately, and there's no "send it in later for your refund."
Always best to ask for a clear explanation of the core return procedure and all associated shipping costs.

NSTAAFL: No Such Thing As A Free Lunch!

You pay the core charge up front, in addition to the price of the part.
Often called a core deposit.
So you pay $39 + 30 up front.
Then you get the core charge back after you return the core.

I live about 10 min. from their store. They're the most decent bunch of guys.
Not to say they never sell something defective. But they've always been great about rectifying anything wrong.
--
Sven: '89 245, IPD sways, electric rad. fan conversion, 28+ mpg - auto tranny. 850 mi/week commute. '89 245 #2 (wifemobile). '90 244 (spare, runs).