Depends on what long range varmints mean in your book.
Tommy, fellow Kalifornicator (me) says you will generally get *less* elevation capability in higher magnification scopes than lesser versions. Cabela's has a nice catalog and decent prices, but you can usually do better if you shop around.
Consider this 3-12 version advertised here:
http://www.nookhill.com/ubb/ultimatebb.php?ubb=get_topic;f=15;t=007907
Dealer cost on the Burris Signature 8-32 with 'ballistic mildot' reticle, Burris product #200861, is $484.90. But that scope has a measly 22 MOA of internal elevation, so it would be VERY challenging to use at long range unless you went with a tapered base AND used the reticle for holdover. I say don't buy it, with no offense to my pal Wayne who posted just above!
Here's what you gotta do: Decide first on your budget -- how much can you spend? If it is not enough to get something good, then don't buy a half-*** scope -- wait until you can get what you want/need.
Once you know your budget, then decide what you want in your scope. Magnification vs. internal elevation, and so on.
Shop the web, and talk with competitive shooters in your area, not just the shmoe who uncases Grampa's deer rifle once a year and fires 7 rounds at a paper plate at 75 yards and says "let's go huntin'!"...
Your .223 is not really adequate to shoot much past 400y, and would require very specific loads and barrel twist to do so. Decide what you're realistically gonna do, and then get the best stuff you can afford to do it with. You're a young guy -- get some experience and spread the word in your peer group after you learn how things work out first hand.
High magnification is overrated once you get past 20x or so. You, the human being component, will not be able to hold any more still using a 42x scope vs. a 3x scope. Think about that! But you'll be able to see things far away with a 24x that a 4x won't do. If you envision shooting to 600y and farther some day (using an appropriate caliber), my suggestion is get yourself a Sightron (yeah, some of you have heard this before) in 4-16x42 or 6-24x42 with mil-dot reticle. They have a reasonable amount of up for 1" tube scopes, and then you can use the reticle for holdover (and/or mount the scope on a tapered base to gain some elevation).
$300 or so on the barely used market. Put a WTB (want to buy) ad out there and you might be surprised.
Another very good value for your type of shooting is the Weaver Grand Slam 6.5-20. Don't know how much 'up' it has, but optics are excellent, and they can often be had for about $300 on the barely used market.
Good luck.
[ 10-05-2003: Message edited by: Nate Haler ]
[ 10-05-2003: Message edited by: Nate Haler ]