Figured that out a few years ago with acoustic guitars. Couldn't figure out why guitars cost so %$#@* much, had the opportunity and a one year assignment to Panama without the family and said "lets give it a try." 8 months, $500 in materials and about 300+ man-hours later, I learned why acoustic guitars (the good ones) are so expensive, of course a lot of the time would be better spent if you do multiple items simultaneously, but still.
Now, if a friend sees mine and asks what it would cost for me to do one for him, I tell to go to one of the guitar shops find the most expensive guitar in the place add about 25% to the price. If he is still interested, we will talk.
You're right until you actually sit down and do it, you really have no concept of what goes into a project (to do it by hand).
The ones I really feel for are the custom cabinet guys. I went to a dental equipment mfg for a class once, they also make all those cabinets you see in the dentists office. The guy in the cabinet shop was showing me how they cut wood. Tell the computer which cabinets set you want, feed in the stock listed on the stock listed on the screen. The machine cuts and marks all the pieces and spits them out the other side, takes about 10-15 minutes. Try that on a table saw!
John C.