This Frequency Counter:
(a) works well into the RF range (I tested it to 50MHz and it was solid, unlike some of the posts here which stop working at a few hundred kHz)
(b) is extremely cheap (around $10),
(c) is portable, battery powered, and hand-held, and
(d) uses common components that are stocked at mouser.com so anyone build one! It’s based around an ATMega16 microcontroller reading frequency from a 74lv8154 dual 16-bit counter (acting as a 32 bit counter) and displays frequency on two multiplexed 3 character 7-segment displays.
$10 Frequency Counter – [Link]