I think its high priced.
You will almost always end up getting new tubes, tires, fuel line, in-line fuel filter, petcock, the 4 cables, a needle valve, fuel filter IN the carb, and a new banjo, so plan on spending around $150 to HOPEFULLY make the thing run, safe, and not leak fuel.
If you already have the tools to rebuild a Minarelli V1, at the bare minimum, new gaskets, seals, bearings, and rings will probably run you another $85, so now you are around $235 for a safe, running bike with a good engine.
You will want to try putting in some elbow grease shining up the chrome everywhere and you will certainly want to grease the wheel bearings and the fork bearings.
Is the gas tank clean and leak free?
Are you gonna want to paint it a custom color?
This engine stock at best only goes 30 miles per hour with the 11 tooth sprocket, so then you will want to kit the engine, and treats has a kit with everything you need for around $570, so now you are up around the $900 mark for a safe, fast bike, plus the $375 you paid for it, bringing the total up to $1300!
By then you will have fallen in love with it and want 15 more mopeds, but you don't have a garage so you bring them into your basement. The 15 more cost you around $4000 and the engines all need rebuilding and that will cost you $3000 cuz it's never just the rebuild kit's and rings, it a flywheel, a stater, a clutch, a starter clutch, an output shaft, a cylinder, a piston, a sprocket, a head, light bulbs, a tail light resistor, a tail light assembly, a tail light lens, a headlight bucket, a sealed beam bulb or just the headlight lens, because all the 40 year old reflective material has flaked away and you can't see to ride at night, and a kill switch, and a headlight/horn switch, and a new horn even though you can barely hear them over the engine sound, and one or two mirrors, and a speedometer cable, and the speedometer gear, and cranks, and pedals, and cotter pins, all for each of your 15 bikes, and now after 4 years you've spent about $8000 on 15 bikes, but like someone said on another post, you don't have 15 asses, and none of your kids will ride with you, and your wife gets mad at you, so you take a picture of a moped on her bed because you are sleeping in separate bedrooms, and then you find another bike you just gotta have....
Run! Run away from mopeds as fast as you can!
All that said, offer him around $200 American and enjoy a really fun hobby, but try to keep things in moderation.
Welcome to this site and to mopeds! (edited)