My vote is oil injection
Tbh, I went from zero Tomos knowledge to rebuilding an engine from bottom to top in about a month with the help of people here and some parts (and advice) from treats (treat land.tv if you haven’t been there yet). If you don’t have a decent tool kit, factor in $200 or so just to be safe. I wouldn’t worry about whether you CAN fix the issue, but more of DO YOU WANT TO.
My biggest advice is that if you want something you don’t have to work on, get a scooter (Honda IMO). If you want something you can do maintenance on and learn with (possibly upgrade) go with a moped (Tomos IMO)