There are many good brands.
Agilent, Fluke, Microtest, Tektronix, Wavetek, Datacom, BK Precision, Ideal, Harris, Progressive
I don't know how you can get a decent cable tester for under $100.
If you need more information besides continuity, crossed wires, wire mapping, a more expensive tester is recommended. The last three brands above make some less expensive 'continuity' type checkers. (Not usually real TDR's, but more like tone generators and can sometimes detect some anomalies.)