Where are all the space capsules?

Question

My understanding is that space capsules, at least until recently with the private companies, have been single-use. Including the Soyuz capsules that Russia keeps using. Which means there could potentially have been any number of used capsules for sale at reasonable prices to science museums, universities, and other venues around the world. So why isn't there a Soyuz capsule at my local science museum, where I could wait in line for a chance to sit inside and flip non-functional switches? Whatever they've been doing with their used capsules, it seems that selling them off to space enthusiasts couldn't be the worst thing.