I couldn't find any 17-21" portable monitors last time I wanted one. They seem like a no-brainer to me, but apparently there is no market for them? It's either

I couldn't find any 17-21" portable monitors last time I wanted one. They seem like a no-brainer to me, but apparently there is no market for them? It's either 13 inch and overpriced or full fledged desktop monitor...