foldable bike

Hello people.I m really new to ebikes world and i need your help. I want to get an electric bike but my budget is below 500 euro . I live in a city where we have up roads and its not flat at all. I am 80kg and 1.80 weight and here is two options i have in my mind right now. The first one costs...

if so how would you go about it? would it be as simple as welding or even gluing some sheets to the frame?

I have been debating which bike to buy. I live in a mostly flat area, but some steep hills are a challenge. I want it to commute downtown, but there is not a lot of secure parking in down Philadelphia and a full size bike would make it harder to bring into buildings. I want hydraulic brakes...