I love these, but I recently made the mistake of buying a store brand one, I thought it looked the same, but actually, they don't have the spout quite right and it doesn't pour right, I have to pour my coffee over the sink because it dribbles everywhere.
I should have just repaired my old one, I left it too long on the stove and melted the O Ring, but it should be replaceable
You can very easily get replacement O-rings, I've had my moka pot for about 15 years and I'm on my third ring. The first got lost and the second damaged.
Yes you can generally buy the gaskets, but might need a specialty store to find them. They harden after a while anyway, and there's going to be someone in your life, a friend, housekeeper, in-law, who will throw it out in an effort to be helpful.
I should have just repaired my old one, I left it too long on the stove and melted the O Ring, but it should be replaceable