Excuse my candor, but three shot groups are not that big of a deal, and to put them into 1/2" at 100 yards is fairly common, esp. with Sierra Match King loads. :-)
I'm not impressed with any custom riflemaker that bases a guarantee on three shots, unless its applicable to a lightweight hunting rifle w/light contour barrel. For a long range setup, a Sendero will get it done, believe me, and with match loads, like SMKs, you will be delighted with the five shot groups you can achieve. For paper-target work (don't know how they perform on game animals) you should also consider the Hornady AMAX. Excellent, consistent sub-moa in my rifles.
My price info was a bit off on the Sendero -- the regular version is even a better deal: $550 wholesale for the basic Sendero, and add twenty bucks for the newer Remington Ultra Mag calibers. The stainless fluted version will cost $100 more, at wholesale.
If you want to further stretch your budget, contact MidSouth Shooters and get a Leupold 'LR' base (one piece type, compatible with Redfield style rings) for about $17.00. This base has a forward taper, to add about 15moa to your scope's own adjustment range. Then, get the Burris Signature rings, which can be had with offset inserts to further increase your scope's elevation capabilities (and windage even, depending on what you need).
These rings will cost you about $25 in the one-inch size, and $36 in the 30mm size.
Top it off, if you dare, with a Tasco SS16x42 or SS20x42 (an excellent, top quality scope built to meet/exceed military specs), which can be had from SWFA for about $300 new, or a bit less on the 'hardly used' market.
These scopes feature a 30mm one piece maintube, fully multicoated optics, etched glass mil-dot reticle (which can be used for holdover AND range estimation if you like), and parallax adjustable, with target knobs. Completely waterproof, and the best value in the optics world that I've yet seen (and used!). Bill Wylde (of 'Spacegun' fame) has used one of these (in 20x) for two years running to finish in the top group at the prestigious Canadian Fullbore Championships, and he knows his equipment. [img]images/icons/smile.gif[/img]
So, for 'Value', get a Sendero and the bits described above, and you will have less than $1,500 into the whole rig, with money left over for best quality ammo, bipod, and range time.
Lastly, Jacob Gottfredson, writer for Precision Shooting magazine and 'The Accurate Rifle', used a factory unmodified Sendero to place in the top four in the National 1,000 yard benchrest championships a few years back.
Think about it! I've got custom rifles
too, but these Rem 700 heavier barreled rigs can really be surprisingly good. My VSSF (in .308) is a proven winner, and I wasn't shooting against guys using SKS rifles either. [img]images/icons/wink.gif[/img]
Good luck, whatever you decide.