You need to spend above $1500 on a scope to see a noticeable difference from the Conquest. Something along the lines of the Zeiss Victory, Swarovski Z6, S&B Zenith, Leica, etc. Even then, in broad daylight there may not be much difference, but it's at first and last light and higher magnification where you'll notice.
The folks over at the SWFA and opticstalk forum set up a manufacturers rating scale a few years back and I'd say it's pretty accurate, except for the fact I'd place S&B into the top line;
Leica ER, Swarovski Z6, Zeiss Victory
Kahles C - CL & CSX, Premier Reticle, Schmidt & Bender
Kahles KX, U.S. Optics, Swarovski PH & American Lightweight
Bushnell Elite 6500, Leupold VX-7, Nightforce NXS, IOR Valdada, Vortex Razor
Bushnell Elite 4200, Leupold VX-3, Nikon Monarch & Monarch X, Zeiss Conquest
Leupold Mark 4 VX III & VX-L, Meopta, Nikon Monarch Gold & Titanium, Sightron SIII & S2 Big Sky, Vortex Viper
Burris Black Diamond Signature Select XTR & Euro Diamond, Pentax Lightseeker, Trijicon Accupoint, Weaver Grand Slam
Bushnell Elite 3200, Leupold VX-II, Millet Tactical/Buck Gold, Nikko Stirling, Nikon Buckmaster, Sightron SI & SII, Vortex Crossfire & Diamondback, Super Sniper Fixed
Burris Fullfield II & Timberline, Leupold Rifleman & VX-I, Leatherwood, Mueller, Nikon ProStaff, Simmons
Barska, Sightmark, Swift, Truglo
BSA, Tasco, Yukon
ATN, Leapers, NcStar