The 7800 had 59 games released for it, so for most it’s an irrelevant console. Being able to play 2600 games is nice, but not worth the $100 or so someone would charge you for the system. From a value perspective, the NES is a much better bang for your buck as it has a monster library of great games that have tons of replay value while the 2600 is an arcade machine with quaint single serving experiences.
7800 is the best bang for the buck. 2600 games + 7800 games.
If you have a Genesis or a Game Gear, all you need is an adaptor for Master System games.
https://www.howtoretro.com/emulation/sega-power-base-converter/
https://handheldlegend.com/products/master-system-player-for-sega-game-gear
The 7800 had 59 games released for it, so for most it’s an irrelevant console. Being able to play 2600 games is nice, but not worth the $100 or so someone would charge you for the system. From a value perspective, the NES is a much better bang for your buck as it has a monster library of great games that have tons of replay value while the 2600 is an arcade machine with quaint single serving experiences.