I know you said you wouldn't buy much, kajero, but since you mention that the grocery store is close by and you only have one bike I'll make another pitch for a trailer. Eden is right that it is not what you want for small loads or long distances, but for regular grocery shopping at a store not too far away on flattish terrain, I find it unbeatable. I bike down to my local store 600 yards away, and can sling 5 bags of groceries right into it without any repacking. It's faster and easier than using a car or walking with a backpack.

My Burley cargo trailer can be attached to any bike, as the attachment point threads on just inside the quick release of the rear hub. I do need low gearing, though, it adds drag up even the smallest hills. But it's stable as all get out. Plus, it impresses the neighbouring kids

But, a new bike is never wrong