I'm coming up to my first full year of biking as my primary mode of transportation, and have a dilemma of biking vs walking/running for the coming winter. In January I bought a crappy mountain bike and was thrilled with the resulting freedom of getting around so easily. Now the chain is completely rusted, the frame creaks ominously with every pedal stroke, and the LBS recommends a new chain, freewheel, and (used) 5-speed cogset for $55, which is more than I paid for the bike. Plus, the bike is too small. For winter riding, the LBS recommends a single-speed with narrow tires (to cut through the snow) for about $400 and the expectation of i) replacing the chain and freewheel after each winter and ii) replacing the entire bike every 5 years or so. I would hope to get more years out of the bike by following the advice here on the forum, but it still sounds like about $100/season for a winter bike. I've been watching kijiji for a few weeks, and I'm wary of buying used because I'd like to benefit from the LBS's advice on getting a bike that fits properly. The LBS I have in mind does have used bikes, but there's obviously still a markup.
I work from home and my only required commuting is taking the kids to their respective spots - which I can do with a jogging stroller and lots of encouragement for the older ones to walk when necessary. Everything I need (e.g. groceries, library, school/daycare) is within walking distance, but I would miss out on loss-leaders from stores that are easily accessible by bike but a bit too far otherwise. One of my favourite exercises right now is to plan our menu around what's on sale and then ride around picking everything up. I'm not sure that our savings from the loss-leaders would add up to $100 over the 3-4 months of winter; I mostly do this extra riding because it's fun.
What do you think: is it more badass to (a) save the money on the bike, build up my running muscles, and adjust for a reduced set of grocery stores, or (b) invest in a sturdy set of winter wheels?