I had one just like that, same color 1970 CB750. IIRC it cost $1495 from the dealer. Each year each model came in the same color, again IIRC. This year the 4 carburetors were actuated by a special 4x1 cable... I changed to the setup used later with one cable only to operate a pivoting rack of "fingers" each of which operated one carb for much less hassle synchronizing them. I also put on a Vetter fairing and a luggage box above the tail light.
My big adventure was a solo road trip from Seattle east to about Davenport WA. north into Canada to Sicamous BC, east through Canmore, Calgary, Moose Jaw Saskatchewan. Yes, with such a name I had to stop there for the night. Had a pleasant chat with the guy who ran the city campground. He related his big adventure riding his Honda 90cc all the way to Vancouver BC and back! Crazy. Somewhere along there in empty grasslands getting on towards evening I ran out of gas. There's a trick in such cases to stop and tip the bike far to one side to drain the gas trapped in the tank side opposite the petcock. Got me just enough gas to get a few miles down the road to a blessedy still open gas station. At Brandon Manitoba I turned south into North Dakota, enjoyed a dramatic display of lightning, spent the night at Aberdeen SD. Then I knocked on a door in Watertown SD in search of an old girlfriend (Paula) but her mom said she then lived in Minneapolis, too bad. I proceeded west through Pierre SD and had a scare climbing out of the river valley when I foolishly criticized a slow vehicle holding up traffic. They took offence and chased me a ways and I was low on gas. I settled in Rapid City for a few days visiting the folks at the camera shop where i had worked part time in 1965-66 while stationed at Ellsworth AFB. The road took me to Salt Lake and a run out onto the salt flats, then Reno.. There was no speed limit in Nevada back then, whee! In Sacramento I put on a new rear tire, then north home to Seattle. 5300 miles in 10 days! Oh, I had my little Olympus 35RC with me but didn't use it much.