----- I have yet to see an e-bike "Black Friday" sale, but then I haven't been looking for them either. E-bikes are kind of a specialty item and specialty items are less likely to be on sale on a national bike sale day like "Black Friday" or "Cyber Monday".

----- The main piece of information we are missing that make a decent recommendation to you is what kind of hills you need to be able to climb during the 4-km commute of yours. With e-bikes what kind of hills you need to be able to climb can be one of the most important considerations to consider before purchasing a bike. Someone that travels over flat terrain and has no hills of any significance to climb and doesn't carry much of anything besides themselves on their bike can get away with just a tiny smallest size 200-watt hub-motor where as someone that needs to climb a lot of really steep hills (like in the U.S. city of San-Francisco for example) needs a motor that is many times more powerful and would probably be better off with a mid-drive where the motor hooks up to the bikes chain and runs its power through the bikes gears so it can be geared down for hill climbing instead of just going with a hub-motor.

----- Does the bike need to be a folder to fit on that train?