Personally, if you're looking to explore the full range of the .300 wsm, I like to mount something in the teens for magnification. Yes, you can get by with a 9 or 10x, but going to 12, 15, or 18x isn't overkill for that caliber and those distances. If you're looking for a scope in the price range that most would consider "appropriate" for a rifle of that quality and price, and based on the previous comments, here are a few to try out:
1. Schmidt & Bender Zenith 3-12x50 FD9 reticle
2. Swarovski Z5 3-18x44 BRH reticle (or even Z3 4-23x50)
3. Zeiss Conquest HD5 or V4 in 3-15 or 4-16 w/ ballistic reticle
4. Leupold VX-5 HD 3-15x44 (plenty of reticle options)