I'm planning on participating in SR this year, including CQB, and I've been looking at different optics for a while.
For CQB, civilians can get away with the Bushnell and Vortex red-dots.. not necessarily the same quality as an Aimpoint, but at least half the price. The downsides to the lower-end optics are battery life and (arguably) durability. For professionals, the Aimpoint Comp4's and H1/T1's are the latest generation of top notch red dot optics. The Eotech is a holographic sight, but in the same class as an Aimpoint. Pricing is ~ 30% less. I strongly suggest you visit a shop and check out the optic before you buy -- you may be surprised by what you prefer.
Also, factor in the cost of a mount if one is not included with your optic. That can add $80-120 to your final bill.
For SR & CQB, 1-4x24 or 1-4x32 optics seem to be the best. Illuminated reticles are preferred, but not necessary. The "lower end" start with the Millet 1-4x, Falcon 1.5-5x and the Leupold AR 1-4. Viper has the 1-4x24 PST coming out in Canada this month, consider it more of a mid-range scope in pricing. Other forums based in the US have user-reviews of it.
Like all optics, the more you invest, the better optic you'll have. The Trijicon Accupoint 1-4x is apparently great, and Nightforce's are considered top-tier. Ballpark $1000-1500.
For SR exclusively, most folks seem to recommend 2.5-10x, or greater magnification. Again, you can spend $400 or $2000 easily.
If you feel like having the latest greatest toys, the new series of 1.1-8x scopes is reaching the market place. Expect to pay top dollar for those though.. $2500+++. S&B, Leupold and Premier are the ones I've heard about.
Good luck.
-- L.