Seems like every couple of months, someone starts one of these threads.
What to collect and how much to collect is a personal choice, we all have a certain amount of disposable income and we all have to do what's best for us, buy what we can afford and stay within our means.
The part that I don't get is if price is starting to become a barrier, what does selling what you already have bought and paid for solve? You bought it, enjoyed collecting it, having it, possessing it, now you sell it? I've been collecting 20mm toy soldiers all my life, I switched from plastic to metal about 15 years ago, I love every item I have, would never, ever considering selling any of it. I still buy figures, vehicles, terrain an add to my various collections. I enjoy the hobby a great deal, I love it as a matter of fact, space is not an issue for me, the basement is mine, it's all mine for my collection.
All I can say is collectors come and go in all hobbies, some stay in it for life, others are here for awhile then fall off the grid, some come back, others never return.
It's a personal choice; if you are fine with unloading your collection and are happy that you now have SO much more room (for what, I have no idea), then at the end of the day, that's all that matters.
Best of luck to all of you no matter what you decide to do.