Actually, the weight restriction was eliminated from the final version of the rules once they were released. (See the CMP forum).
However, the problem is, the actual scopes that will be in use (ACOGS), will cost more than the rifles!
I'm told the best non-ACOGS option is the Vortex Viper PST 1-4.5x. Still, a $500 scope.
Added; ( I'm told by the CMP people that it was the Marine Corp teams that successfully lobbied to have optics permitted, to specifically allow them to use their ACOGS so, I doubt that a 3.5 ACOG will be disallowed.)
I just bought my first "entry" level rifle to start competition with.; a Rock River NM A4 with 1/2moa detachable carry handle sight assembly and Wilson 1/8" Heavybarrel. Weighs ~14lbs with stock and fore-end weights.
I mounted a 6-24x scope for load development and break-in, but find no practical advantage to the scope in actual match shooting.
Heck, at CMP Talladega, I don't even see need for a high power spotting scope as the winds aren't that tricky. Range faces south and prevailing winds are from North West and are usually only 1/4-1/2 value, and typically less than 10mph.
I don't think equipment is the problem. It's the logistics of, and expense of getting to the range, and dealing with the "personalities" involved that hurts the shooting sports!
From what I've heard over the years, I'll probably never shoot at River Bend (near Atlanta).
Still trying to manage to make it to one of Creedmor Sports monthly Talladega matches. Seems they schedule their matches on weekends I'm tied up on... And I'm retired!!!
When did I EVER have time to work???