One of the biggest limitations on me riding my bike is that I can't carry stuff when I'm riding. Having ways to carry stuff on our bikes will directly increase how often we choose to use them for local journeys. We can carry Eva. A basket for the front of my bike means we can now also carry her bag to daycare, and I have been riding her there more often than driving (until I got sick, and it got rainy).
The farmer's market inspired Tyson to make panniers with enough capacity to allow unbridled fresh produce purchasing on Saturday mornings. So far he has made two for his bike, both of which convert into baskets for market shopping. They are attached to the rack with S-hooks of very heavy gauge wire, so easily lift on and off. There is also one small one for my bike - panniers do not fit well around a toddler bike seat, and it had to be permanently fixed on. Shopping trips therefore still require either both of us together, or the car (or many small bike trips back and forward, which I'm not up for thank you, although I do sometimes ride down now for just a few items rather than saving up until we have a big shopping list waiting).
Panniers can be bought pre-made from a bike shop of course, but then they won't be as personal or as well loved as Tyson's creations. I'm still trying to convince him to let Eva weave coloured ribbons into the wire mesh but he is unimpressed by that idea so far.
Initial Time: The first pannier took about three hours, plus shopping time. The second one took only about a hour, as Tyson had perfected the art. The little third one was a fiddly job using leftovers from the first two, so also took about an hour.
Initial Cost: front basket - $10; $16 of mesh per pannier, plus wire (about $21 for a roll of about 30m, so about $1.50 worth of wire per pannier). The small pannier was scraps from the bigger two.
Ongoing time or cost commitment: Zero cost. Time commitment is our commitment to use bikes over quicker, more polluting transport means. The baskets weigh 1040g and 1120g each so there is a small weight increase for riding (obviously more when they are full!) but they are fairly streamlined and don't add too much wind resistance.