There's no new electric car for less than €17800, in the Netherlands at least. The BYD's start at around €20k. Only the Dacia Spring and the Leapmotor T03 are available under that price point. So if something was to be available for €15k and if it's highway capable, I'm sure it will sell decently well.
The BYD Seagull (a.k.a. Dolphin Surf) retails for €10K in Spain. The price difference elsewhere is most likely due to taxes and/or import duties.