The reality is, that most people do not beat a rifle in the woods bad enough to worry about the extra moving parts issue. If you are a tactical shooter (swat, military, etc) you might get a fixed, or go ahed and spend the BIG money on a variable. Personally, and I am a tactical shooter, I prefer the variable power. It is nice, to be able to lower the power if you are shooting close cover, and to jack it up, if you are shooting distance, or want to better ID something.
I strongly recommend the Nikon Buckmaster. I had one in 4.5 x 14 power. I shot it in Sniper Competitions around the US, and used to hunt. Shot it from 50yds, out to 1200. Cost wise, not too bad. Less than 400 if I remember right. I bought mine about 6 years ago at a Bass Pro. At the time it was the best I could afford, and now, comparing it to a $1000 leupold Mk 4, I wish i had it back. Don't buy into the school of though that more expensive is always better, or that variable isn't worth anything. Just my $.02

good luck