But in general, any bike that doesn't look like it could sell for 15 euros on the street is a target. The nicer it looks, the more likely a target.
If you're out on the streets often enough at night, you'll inevitably be approached by someone offering to sell you his bike for cheap. Hint: it's not his bike. But the nicer bikes get sent off and sold elsewhere.
Most people I know either keep their bike in their house at night, or they just accept the reality and buy old crappy bikes that they won't cry over when they go missing.
But the expensive features I would like are a comfy but light saddle, a light but sturdy frame (double butted steel tubing), belt drive, and ideally a small motor/battery combo for times when the wind really sucks. Since you asked. Christmas is coming up soon :).
What expensive features do you need?