When the economy and housing was booming, lumber supply stores had just about anything you could want and certainly the typical supply needed on the shelf but as the market crashed, the supplies dried up. No lumber supplier wanted to be left holding a lot of merchandise so they slowed their buying and sold everything they could, even if it was the junk lumber that laid at the bottom of the pile for the last year, maybe two. It wasn't just the local lumber suppliers, it was the manufacturers too. The manufacturers slowed making their products and shipped what was in stock, even if it was what they would typically "cull" out of the mix. We got a lot of trash wood until they finally sold out of old materials.
Then came the second wave of the problem, lack of product. Now materials that were considered "stock" items are considered "special order" items. With special orders you have to wait for the product to ship from somewhere else or worse, be manufactured on demand. Then of course, if you need to return any because you over ordered the suppliers or manufacturers will hit you with a "restocking" fee or not accept any returns on special orders. If you under order and have to order a handful more to finish your project you could wait for weeks or months until the manufacture gets a large enough order to justify making more. How does a contractor factor that into the price? Do we over estimate the materials and hope to return materials for credit if we can or order our materials as tight as possible and if we need to get more, delay the project? Either way, the client will not be happy or the "fluffed" estimate could cost the contractor the job.
Of course to go along with all of these hassles of special orders comes the increased price in the product. Now, it cost more to manufacture because it's not being made as often as it was and the price of gas has gone through the roof and it doesn't matter where it is manufactured and shipped from, it's a considerable distance from where we are in the mountains of North Carolina.