I worked during my college years for a custom frame shop, and, yes, it was (and is) very expensive. The pictures I have from back then still look fabulous, though, and I'm glad I had it done. If you don't want to pay for custom, then you have to mat your picture up to a standard size, and that can look a little funny, also.
Trends come and go, and expensive pictures/framing for the walls doesn't seem to be quite the thing it once was. I do watch at auctions and estate sales for quality vintage frames, even if the picture is junk, because I know how much value is in the frame itself.
Terri