It was a "limited" edition. Not really limited, as it wasn't even intended for production, they just built some of them (don't know how many they were required to) in "street legal trim" to be able to enter them in the 750cc category.
That kind of vehicles are called "homologation" vehicles, that are street legal versions built in extremely reduced numbers just to get them aproved for an X race series. You can find examples of homologation vehicles being motorcycles or cars, they are most of the time rarer than limited editions, as there are a limited number of them, with extremely race-ready setups (most of the time just replace a few bolts and you've got a race ready vehicle), and most are pre-sold even before they hit the market.
In the case of the R7 it was only available to racers, with licenses and that could prove their involvment in "serious" racing.
Kind of what Ferrari did with the Enzo. To be able to be considered as a buyer you must have a F40 and a F50, then Ferrari had to aprove you, that was the only way to get the car. So people bought them for half a milion and could instantly sell them for almost a million (or something like that, those cars doubled their value after leaving the showroom...)
