I think it depends about storage of screens. Would you leave 5 brand new newmans sitting on a shelf for over a year because a customer tells you they will 'definitely' want to order more? Infact, the more someone tells me they definitely will order more, the more inverse the likelihood it is that I will ever hear from them again!
Apart from the cost of storage space, it wasn't so much of an issue with cheap wooden frames, but I think there is more of a trend for quality print shops to reclaim their quality screens because otherwise they end up with thousands of dollars of investment stored away and unavailable to use.
We try to be as efficient as possible and that means reclaiming screens. I know a local shop that probably would save screens away, but you should see the screens they use for that - floppy, warped screens with detached mesh in several places. The prints are terrible. So now their regular customers get the worst screens and prints because they want to keep their best ones in circulation! Now obviously this isn't true of every shop, and perhaps it is a one-off case, but on the face of it, they are the better shop because they offer storage and we don't. But then their process prints also come out looking like mud.
We get round the issue by offering a pre-paid monthly screen subscription fee. We'll reburn fresh screens. That way, anyone entirely serious about re-ordering can get matched, tensioned screens at a discounted rate.
So if a shop does not offer storage, ask why. Perhaps there is a very good reason for it. It's not necessarily a bad thing