Here are some misconceptions about RGB that need to die, and why they should.
Misconception #1: You need to mod all your consoles to use RGB.
Truth: No, you do not. The majority of popular consoles after the NES to the Dreamcast will natively support (and take advantage of) analogue RGB. The only notable ones that don’t are the N64 and SNES Mini. Your Master System, TurboGrafx-16/PC Engine, Genesis/Mega Drive, SNS(P)-001 Super Nintendo/SHVC-001 Super Famicom, Neo-Geo AES, Atari Jaguar, Sega Saturn, Neo-Geo CD, and PlayStation all support RGB without modification. Hell, some consoles afterwards support RGB, even though analogue RGB at 15kHz is not ideal for these consoles: the Dreamcast, PlayStation 2, Xbox 360 and PlayStation 3.
Misconception #2: It would easily cost $400 to get into RGB.
Truth: You can get RGB equipment for far less than that. If you want something that will contend with the Framemeister, you could pay $200 for the Open Source Scan Converter. If you prefer CRT televisions for gaming, you could buy a PVM or a SCART to component converter.
Misconception #3: RGB only provides a subtle difference.
Truth (okay, this one is kind of opinion based): Maybe between S-Video or component! The difference between composite and RGB is a night and day difference, especially on a Sega console. RGB lets you see what the console is really capable of.