Ahhh This is so hard - I sympathise sooo much. I wish I lived in a 10,000 ft' house instead of 1000 ft' and then I'd never have to sell anything either. I've sold or given away almost 1/2 my antique radio collection recently anticipating a move in a few years . The plus side is that I've changed the nature of the collection now by stripping out the lesser quality or lesser "sentimentally" valued units and as a result the rest now seem much more dear.
Anyway, I digress (as always )
Based on a couple of your answers : don't need the money, has no sentimental value and don't need the space so you could buy other photo gear, here's my advice :
Sell it and buy something else that will light your fire for while. When you get tired of that one - sell it also and go on to something else. The up side to doing this is that it's always "fresh" and you're always learning about something new.
just more of my $0.02 worth of buttinski