Here are my vacuum tubes. I've been collecting them for over 30 years.

As you can see, I haven't treated them very well. They've been moved from one home to the next several times. Some of them may no longer be functioning. Standing up in the background is a Tung-Sol bridge rectifier, for which I don't have a part number (but the
10D1 looks similar). Next to it is one of my five examples of the
6336A dual triode.
shockwave77598: As can be seen from the linked close-ups, these "vacuum" tubes are full of metal, so it cannot be said that I am collecting tubules of "nothing". The base of the 6336A has a magic-marker annotation "10/12", indicating that I once tested it (back when corner drugstores had tube-testing machines) and it was in good shape at that time.
In 1998 I found a website that sold tubes. I checked their prices and determined that my 98 tubes had a replacement value of about $358. The 6336A is one of the more expensive items, with a "used" price-tag of $25 back then. I contacted the website operator to ask if he wanted mine, but got no reply. I am pleased to be able to recall these tidbits for you, but in order to find this price list I had to search through a CD I made, named "Our Family 1999", that contained all home-made files from the family computer at that time.
Today I checked eBay.
Here is a used 6336A, perfect 115/115 test score, $2
8․00.
This one is never-used for $1
5․00.
This sad sack is the sort of auction my son will have to run if I don't get rid of these tubes before I die: set of six 6336A's plus a single 6336, unknown quality, current bid $1
0․50. Well, at least he's getting bids!
Unlike tubes, it seems
tube testers are now collectable items, costing hundreds of dollars and often out of stock.