I am surprised nobody has made other reply to this.
Anyway here is my $0.02. I have seen and used many different bases and rings prices ranging from $30 to well over $300. Obviously there is different grades in quality and fabrication process and some brands have mastered this over others.
Let's start with bases. We are talking about picatinny rails, made of Aluminum or Steel. Base metal being equal, the specs are all the same as well, picatinny 1913 specs. From personnal experience, a $50 EGW will perform as well as a $200 Near, you can mount you ring/scope combination on them. After installing and using most brand of bases I now use EGW on low to med Caliber Rifle, and Warne for everything else. If you are planning on removing your scope often I definately recommend higher grade base, Warne is an awesome products.
For rings it is a touchy subject to some people. I have used a lot of different brands. I used to love TPS, until I tried the Warne Tactical. The Warne, in Tactical or quick detach are excellent rings, and priced decently. The desing eliminate the side to side torquing of regular desing rings. No need to tight one side, then the other, hoping the reticle stays leveled.
Again if you plan to remove your scope often, Warne garantees a return to zero when using a complete system (Warne Bases and rings), within 0.003" IIRC.
So, if you give me the choice I would use a Warne Tactical bases and rings, but for a hunting rig, Warne bases and Quick detach rings.
Hope this helps