You can get those Rockchip HDMI sticks for $50 on aliexpress, shipping included (RK3288 ones support 4K). They usually ship with Android 4.4 these days. But for $70-$80 you can get a stick with Atom Z3735F 2GB/32GB and have full desktop OS, Windows or Linux.
You will need to pay import tax + handling charge though. Don't know about the actual prices in Germany, but in UK this would cost you another ~$30 on top of the Aliexpress price.
You're right. That may ruin it for some. It differs a lot from country to country, I guess. Where I'm at the moment there is no import tax on <150 EUR items, and handling is 1 EUR.
