Yes many of the 100 and 200 yard shooters will use a straight 36 or higher power scope. Many scopes on the line even in factory class are still $900+ Does that mean you have to be sporting a Nightforce on a factory gun.
I think you can get away with a nice Nikon 6-24x50mm or a Bushnell elite 4200 8-32x40mm.
I would find a local benchrest match in your area and go a few times talk to the guys shooting and see what they are saying about it.
Accuracy is like speed it is expensive.
The dominate cartridges in benchrest are the 6mmbr and the 6mm ppc. They both has a little brother as well in 22 cal.
Also your rest is going to be very important with them running from $600 up to and over $2k. Then you need to figure out how you want to shoot regular or free recoil.
Sinclair Search : Rests, Bipods & Bags : Shooting Rests & Tops -
Free recoil is where you only touch the gun with the trigger finger and lightly with that hand. You pull the trigger and allow the gun to recoil into your shoulder. Many if now all of the short range bench rest guys shoot like this.