In my last town I rode about 30km a week, which prompted me to upgrade my bike from a cheap bike to a Giant Escape R3. The difference was substantial, and makes me seriously consider buying an even better bike instead of saving up for a car. In my new town I ride about 20-25km a week, and I considered going to the nearby town which would be a 50km trip one way.
However I feel the bike tires are already feeling their age, the roads here are often poor and degrade the quality quite rapidly. I estimate I put on around 2000km since I bought it last year. I definitely consider buying more stylish bags and shoes that would also be more efficient, because when I ride without the backpack, the drag difference feels so good.