Tried to be as unbiased as possible to compare and I can't think of too many instances where a foot scooter is a better commuter than a bicycle...maybe in a busy city just for super short 1 block trips to bring it with you on a bus or subway? Pros of each IMO:
-Bike is much faster, more comfortable, can carry stuff with front and rear racks added, less tiring.
-Razor is cheaper, no real parts to maintain besides the cheap wheels, and smaller+lighter so easier to bring with you in places where you can't bring a bike(taxi cab, upstairs, etc).
If the question is like you asked and simply the cheapest with least hassle, it is definitely the scooter. Does that outweigh all the advantages of the bike though? Not to me, and the bike is still much better choice.
If you’re 16 just get a license and a Honda Civic for $500. It’s not hard you just think about it too much. Motorized bikes as a main transport isn’t a good idea especially with someone who doesn’t know things about engines just saying. If you really want to buy the bike and the motor and I guess by saying you want your mom to buy it that means you don’t have the money. Try to get a used 49cc 4 stroke bike that way it’s quiet and you can talk to the guy about price. I feel bad that your parents haven’t saved any money for you apparently.
You don't need to bump fifteen minutes after posting lol. Or at all Tbh.
The two stroke home build mbike is an educational hobby, ideal for people who are interested in learning about the mechanics of motorising bicycles at home. Only well built bikes are good enough to rely on.
Four stroke kits are more suited for bolt on and go.
Have you checked the legality of mbikes in your local area?
You may indeed be better off with a light motorcycle and a licence, insurance, approved helmet etc.
"Tried to be as unbiased as possible to compare and I can't think of too many instances where a foot scooter is a better commuter than a bicycle"
Wshington DC is one of the places that a stand up e-scoot works well. The roads are too dangerous there for motorized bicycles IMHO. A good folding e-scoot would allow you to weave through pedestrians on the sidewalks and you could take it on the metro for longer trips.