Can anyone share their experience with purchasing an affordable electric bike online, specifically in terms of navigating the vast array of options and ensuring a smooth assembly and setup process? What factors should one consider when selecting an e-bike online, such as motor type, battery quality, and gear system, and how do these impact overall performance and durability? Have any of you encountered issues with sizing, fit, or compatibility when ordering an e-bike online, and if so, how did you resolve these problems? Are there any particular online retailers or brands that stand out in terms of customer support, warranty, and overall value for the price? What are some common pitfalls or misconceptions to avoid when buying an affordable e-bike online, and how can one ensure a successful and satisfying purchase experience?