When I was very little, my dad had about a hundred that he kept on a screened-in porch (mostly Miltonias). When I was 8, my parents built a house with an attached greenhouse and he went nuts and probably ended up at over 1000 for a while. Over the decades he's varied what he challenges himself to grow, but there's about an even split of things in pots and things on mounts at all times, going between about 600-1200 (depending on what counts as a separate plant, etc).
For me, I've been apartment-living and moving frequently out of the country for about a decade after college, so its only been since I've been in one place for 5 years that I've been able to reliably grow things (since my conditions don't change every year!). I currently have 16 plants, with 10 on order. I was previously very space limited because I windowsill-grow and that was all that would fit on my humidity trays, but my husband helped me set up some shelves in front of my one prime window, so now he knows there's more plants in the future!
