Depreciation is only happening more and more quickly though, as technology progresses at an exponential rate. I've been excited for a year or two now at the prospect of finding an alexa on ebay in 10-20 years for 50 quid. But by that time it isn't exciting, because something new and amazing has been invented.
I had a conversation with my old man asking him why he isn't buying up all the old tech he dreamed of as a kid now it costs pittance. He doesn't because now we have plasma TV's with HD broadcasts, iphones, DSLRs, etc.
An F35 would be really great right now, but I wonder how long until it becomes genuinely obsolete?