On the other hand, if you have any interest in learning about computers, the RPi offers a nearly infinite range of hardware and software possibilities but all require that you exercise your brain and get your hands a bit dirty.
....and you also get to exercise your wallet as well
Yeah most of my "parts" were sourced out from Amazon, and from local online electronics stores here.
I too have a retropie setup, my very first RPi3B (not the RPi3B+) is now a retropie unit with 128GB A1-class microSD card, lots of games, many of which I may not be able to play in this lifetime....
got myself 2 sets (pairs) of game pads, the retro-SNES type and PS3 type, as well as a "fighting stick".
in the kit make sure you get
1. a good case (better with heatsink and fan)
2. a proper power supply 5.1v 2.5A (better if you can get 3.0A),
for your own peace of mind please refrain from using anything labeled, called, or marketed as "chargers". whatever others tell you otherwise, stick to using proper power supplies for the RPi boards.
if the kit includes a microSD, you may use it for test-run of the system, then get yourself a good branded and reputable microSD card rated minimum Class10, recommended is A1 class. Stay away (as in several billion light-years
) from A2 class cards.
some online store carry/sell fake cards (marketed as, say, 128GB, but the only usable part is about 10GB when tested with a microSD card test app), so be careful of those.
if the kit you fancy has some electronic stuff (like resistors, LEDs, switches, etc) then that's the part where wh7qq suggestion goes... which is a good alternative to just gaming (if you do get bored of gaming, that is
ah and dont forget the most important part..... have fun!