If you think you won't be cycling to get to work, to do shopping several times each wk. maybe 1 pannier would be fine.

I frequently ride with 1 pannier and just ride with a very stuffed, overweighted pannier because ...I'm just lazy to carry around 2 panniers. It's fine if you are a regular rider. I don't leave my pannier(s) on bike rack. I know others do.

But having 2 panniers won't make you hesitate to cycle with heavier loads and to go on trips!

so think about the type of riding and for the different purposes of cycling in your life...once you've finished eyeing your favourite pannier line.