On 19th July 2017, I bought a Casascius for $3'000. (A Casascius is a rare physical brass bitcoin). The price of Bitcoin that day was around $2000, so I was paying around 50% premium or $1'000 more than the value of the I BTC inside the hologram. It's worth it just to own that rare piece of bitcoin history. Imagine my joy, as I watched the bitcoin price soar on the 19th and 20th. It didn't take many days before the premium was fully absorbed by the price rise. Based on the extremely rare Ebay bids, I reckon the coin is now worth $10'000 to $20'000.

I thought I deserved a reward for my prescience in buying the Casascius coin. So.... I went on AliExpress and bought myself some boys' toys. Here are the fidget spinners I bought:

Next to each spinner, I have written down two pieces of information:

1. How long it spins (The spin time is the best of 3 spins for each one).
2. How much I paid.

Conclusion

The most expensive spinner ($23.72) also span the longest time at 5 minutes and 40 seconds. (The website rated it at "up to 7 minutes).

An equally long spin (5:40 minutes), came from one of the cheapest spinners ($3.56).

Overall there appears to be only a limited relationship between the price paid and length of spin

If you are going to choose a spinner, then unless you want to win a record for balancing it on your nose for longer than anyone else, you may as well concentrate on the looks rather than the spin time.