Depends on so many things - principally the distance you ride, but also the riding conditions, how you store it, whether you keep it clean, whether you can do m

Depends on so many things - principally the distance you ride, but also the riding conditions, how you store it, whether you keep it clean, whether you can do minor/moderate service yourself. Personally I budget about €200/year for my €1200 road bike for 2000 km/year. I store it indoors, ride it 20% in the rain, don't take great care of it otherwise, and take it to the shop for anything more than changing tubes/tyres.