I should have invested

Around five years ago, I bought a CD. The Edge by Eternity X. The album quickly made it into my all-time favorites and is still one of my top five.
The CD is so obscure that the only place you can hope to buy it is on the internet. The going price there (five years ago) was a steep $18. I found a deal on a slightly-used one...$14.
Recently, the band, who was supposed to release a new album recently, has disappeared off the radar. But in trying to find them, I discovered that The Edge is going for $45 on Amazon. Now, Amazon sellers sometimes over-price things, so I checked ebay. One used CD for sale...and it sold for $40 (plus shipping and handling).
Five years ago, when I knew that this album was incredible, and that there were limited copies being made, I should have bought numerous copies. I could've made some nice cash.
Why don't I sell the one copy I have?
Because it's incredible music. Because it's worth $40 (or more) to me. And you know that we're in economic hard times when Starbucks shuts down numerous stores and people stop buying SUVs and monster trucks.
But they're still spending big bucks for this CD.
Hopefully, next time, I'll know to invest.
Oh--and if a bunch of just-graduated kids from BHS love this album, I swear I have no clue how they found out about it...