Are we sure this is economically unreasonable? I think this happens in many financial systems; all you need is for a price increase in one place to cause cost increases at a delay (ie, fast inflation), eg: by workers getting paid more so they can afford the aforementioned price increase.

(We should also note there are markets that don’t do this. Air travel is a notable example.)

More interesting to me is price spikes when there’s no actual increase in costs. Several of those as of late.