Just curious, is this for a varmit rifle? Why such high power, if not? Personally 10 power is more than plenty IMHO for a biggame scope and it opens up your options more with the budget you have set forth. I also like the ability todown to 3 or 4Xin the field as conditions/situations dictate.
Also have you ever owned or shot a 50mm scope? If not, why the 50MM objective? The reason I ask is this will require high mounts and may hamper your cheek placement/shooting ability! This should also be coinsidered IMO.