I think the plumber is trying to pull a fast one. Try the attached link. Select Copper under "End of Day Prices" and then click on "Year" on TimeFrame. Click the chart to download a PDF. The price for copper pipe ought to more or less track the commodity price for the metal. I don't see a doubling or tripling since March but it is up somewhat.

Good luck. If number two plumber doesn't jerk you around I'd send the first guy packing and tell him it's because he wasn't being honest up front. They never get more honest once you have them on the job.

Here is a link that might be useful: Metals Commodity Prices

My plumber had sent a notice (i have a copy of it) to our builder saying that if copper remained at the high prices it had been that he would be forced to add a surcharge when his stock of material ran out. http://www.kitcometals.com/charts/copper_historical.html
shows different data than in the link klabio posted. Metal prices are way up- look at all the articles (and posts on this forum) about people stealing copper pipe and wiring for the high scrap prices.
I would not assume your plumber is pulling a fast one, but I would ask him to honor the quoted price and/or discuss Pex or alternative materials. Good luck!

Copper prices have been high for a while as has the related theft problem. With the housing boom now bust, virtually no houses being started nor any resales activity, I am surprised that ANY building materials have increased in the last year. Between the time our house was bid (spring of 2006) and materials being shipped (beginning late summer/fall of 2006) many materials had dropped as much as 20% or more. For example, plywood that I saw the quote on in the bid development was $60 per sheet. When it was delivered, the invoice was at $37.50.

Yes, there has been a HUGE increase in copper prices, but it wasn't in the last six months--it was more like a year or two ago. As I recall, the increase was in the general range of tripling. I understand that the reason for this increase was combination of huge increase in demand from China combined with some problems at mines in South America.

You do know that there are other good alternatives to using copper. We used Pex (I think that is how it is spelled.) It is a very good product that is much cheaper. Our plumber used copper in areas where he felt it was needed and Pex everywhere else.

Joan

I'm wondering what copper prices are expected to do in the future. Although I'm going to use PEX when I build our home, I've actually considered buying my wiring now as a hedge against rising prices in the next couple years. Of course, I'll feel like an idiot if I spend the money now, and copper prices drop....

"I've actually considered buying my wiring now..."

Or a code change disallows the already purchased cable...
It you purchased actual wire (THN, THHN, THWN, etc.) it would be less likely, but then you need to wire in conduit.

Thanks for all your responses. I too thought the large increase was a few years ago, and wasn't sure how closely their purchases followed the commodities. I know when the price of oil drops, it doesn't always mean our gas prices go down!

We met with the plumber at our foundation, and he did suggest a number of ways we could save money too. We told him we were really trying to stick to our planned budget, which was his bid, but we did have other bids. Housing around here is slow, like most everywhere. He's going to let us know if their is any price differance early next week.