For these smaller guys, I think it's a very real nuts and bolts buisiness decision. It's difficult to bill accordingly knowing your costs, much less trying to take a stab at what they might be a year, two, or three down the road. The world is a crazy uncertain place... a bit more so now it seems.
Also, a guy like Sachs... his bikes will be the exact same forever,period. A less rigid builder might actually choose to 'update' his frames periodically. So again, who knows what is coming down the pipe, that might change the cost of a frame two, three four years out. Whatever it may be, be assured it won't make it cheaper. I'm thinking bb30 ,1.5" lower headtube diameters, new tubesets, etc.