Whats the best circuit tracer for the money?
A good thinking brain is the best circuit tracer!
... a 'thinking' electrician can beat any tool .
... a 'dead' electrician can not draw a paycheck .
However, to answer the posting,
Over my 58 years, I have used :
(1) a "neon" bulb + resistor in a screwdriver. Have four from my apprentice days in the 50's. These have been a lifesaver.
Normally a safe "one hand" direct contact voltage tester. The other 'hand' (wire) is your body in the electric field.
Can even do a comparative test 'hot-vs-neutral' on Knob-n-Tube lines
( where there is no ground ) and the conductive soot makes all the attic joists 'tick' hot.
Frequently you can differentiate between a 'bright' hot wire and a 'not-bright' phantom voltage wire.
My favorite at 120/240, is one where I installed a 1MegOhm resistor to make the neon burn brighter, used on 120V/240V nothing higher.
My testor ( at 1MegOhm ) pulls 120 MicroAmps ... which will 'bite' on 440 ( so don't use it on higher voltages) .
(2) a festoon light socket with pig-tails . I used a 15W 240V bulb, wrapped with duct-tape to help prevent breakage. Only for 120/240V circuits.
(3) Most frequently now, I use a 'ticker' with a gain control and the automatic test turn-on beep. Non-Contact. Greenlee, $20.
(4) Sometimes I use a Klein (Wiggy style) which will not burn-up if the circuit goes 'hot' during a continuity test.
Worth its $40 price, but I have had to repair over-flexed breakage in the two cords leading to the two probes.
Last time I added six inches of nylon flex wrap to make the cords less flexible near the base.
(5) Have brought my o'scope to check multi-channel ( 3 phase ) waveforms to see what is really happening. Another story.
(***) ALWAYS, I look twice at the situation, only probe the conductors I should be probing,
and put my left hand in my pocket so I am not accidently 'dead'.
Think About Your Work ... and you will Live Long.
Glen Ellis,