HP-21S - Is it a rarity?

[jebem]

Thank You for your input and advice, guys!

I have just called the shop to reserve the 21S.
I have to travel to Brussels this weekend to work there for the week, but I will manage to collect afterwords.

From these series, I already have a 20S, a 32SII, a 27S and a 42S.
It was easy to acquire them, as they keep appearing for sale everywhere.
The downside is the highish prices that some sellers are asking these days, specially on the 32SII and 42S models.

Even in small villages in Portugal, people now realize the value of "old" machines thanks to Google, so they are not ashamed to ask sky high prices for what now they know it is "vintage" and collectible pieces wanted by guys like myself!

But I tell you that sometimes I get even. Two short stories:

About three years ago, I saw a HP-35S for sale for 10 Euro. I called the seller and agree to collect it on hand.
Then I asked the guy if the calc was working, and he was not sure about the state of the calculator.
I had a quick look and understood what is going on - RPN fooling the seller into thinking that the machine was defective!
So I ask the price again, and the guy sold it for 5 Euro, with the cell batteries, of course!
The machine is in pristine condition, despite not having the printed guide.

More recently I saw a collectible CASIO FX-3 for sell at a local Internet auction site.
So I called the seller, and the asking price was 15 Euro (they usually align the price with the other non scientific desktop calculators, ignoring the real value of this treasure...).
The calculator was working fine, but I played the dumb guy and I managed to bargain the price down to 10 Euros.
This one was sold to a real collector in Europe for a little bit more money than what I have paid for it.