There are many different cost/time levels of framing. Taking a photo to a custom frame shop is the lowest time and the highest cost. They basically do the design, consultation, mounting, and final assembly right down to trying to get rid of that last pesky piece of dust under the glazing.
Next level is buying premade frames. The frame components are all made for you, but you have to do the mounting and final assembly yourself. The least expensive of which are made oversees and imported in bulk. Although these have the lowest cost, you have little size options, and they are seldom very archival. You can also get premade frames from do-it-yourself frame wholesale suppliers like my company. (Many thanks to our customers for mentioning us in the thread by the way).
The next level is where you start to buy some raw materials and doing more yourself. Starting with just cutting your own mat board (we started selling full sheets a few months ago), to actually cutting and joining your own moulding. This allows the most saving in money per frame, but costs the most in time and can have significant up front equipment costs. Depending on how custom your frames are you may be better off trying to buy in bulk. For example companies like mine have huge discounts for mats at qty 25 which significantly reduces the savings over buying sheets and cutting yourself. Regardless, you have to try to determine what the dollar value of your time is. In my case when I started Frame Destination, I bought pre-cut mats in high volume until we have the revenue to support computerized mat cutters. Personally, I have never hand cut a mat…I would rather be out taking pictures but there are those who enjoy working with the equipment and cutting their own mats.