Yes, but a low starting investment makes the restoration less painful. 
True That... Not sure what I do is called "Restoration", More like Running Roadworthy and Honest. I pretty much Get the ugly off Clean and detail and focus on the Mechanics.
My quick experience now tells me count on a base of:
$40 or for Degreaser, Cleaners Steel Wool and little brass & steel brushes.
(+-) $300 to get engine running and ready. (Battery, Oil/Filter, Plugs, Carbs, Fuel Filters/Lines, Air Filter, Petcock, Cleaners)
(+-) $400 to get roadworthy. (Tires, Tubes, Liners, Cables, Chain, Brakes, Fork Seals)
So about $750 in any Non-runner / Neglected "Barn Find" Bike, Then your lucky if these items correct what may have brought it down years ago...otherwise additional expense to repair/remedy.
It does bother me that the CB750 got painted to match the Vetter Accessories, I will probably pop for a repaint back to original Emerald green some day.
The chrome and black frame were in exceptional condition under 26 years of dirt & dust. I did trade out the front fender from a '78 750 I had parted out since it was in better shape. The "Brat" style seat i had laying around along with the weathered Tank & Side Covers fit well with the vision I had for it. The fading on the tank and side covers is the kind of thing guys try and duplicate/fake I decided to embrace it, even helping it a little, the left side was just beginning to show the orange through the black in the knee area and it looked "cool" so I helped it along, then worked the right side to match. Funny thing is after I photographed the bike I saw the "face" in the tank
