I used to buy fixer-upper ebikes because I enjoyed fixing them up, building new battery packs and so on. After three got stolen and one broke in half, I bought a brand new folding one. While it cost more than all the previous ones combined, it’s been so nice not to worry about it breaking down (except for flats), and having warranty cover for any issues that do occur. It also has a really solid lock and chain, and is easy to bring inside for safer storage, or to take with me on buses and trains.