There is no right or wrong answer here. Are we talking about collector value or just user satisfaction? Value is a strange thing. Should you buy the knife you like or the one that will increase in collector value? I like to use and enjoy my knives so I would lean towards user satisfaction as my measurement of value. It took a year for the SB Stretches to sell out and I cannot say that they have skyrocketed in collector value since then. If you are a collector then maybe a knife gaining $50 in value is a plus. I might say that that just barely offsets the fact that the GB2 is hands down a better value in the first place as a user. If you are gonna put it right to the stones and use it then buy which ever one tickles your fancy. The HAP Stretch isn't a CF Para2 and if it ever did double in value it would take years and have to still be new in the box and what fun is that. Value is all perception.
I never said there was a "right or wrong answer here". The OP said he liked the Stretch in the first post and since he likes it I said he should keep the Hap 40 version because when there gone there gone and buying another one a few years down the road will most likely cost him more. Conversely I also said if he didn't like the Hap 40 Stretch to sell it and get the GB2.
"It took a year for the SB Stretches to sell out and I cannot say that they have skyrocketed in collector value since then."
It may have taken a couple of years or whatever for them to sell out but looking at recent closed Ebay auctions and BIN's paints a different story. They are slowly going up. The same thing will probably happen with the Hap 40 version a few years from now. If anyone wants a Hap 40 Stretch right now is the time.
"I might say that that just barely offsets the fact that the GB2 is hands down a better value in the first place as a user."
Again, subjective. I've already had then returned a GB2 and in my totally subjective opinion, it wasn't nearly as good as the original GB. I'll even take the Stretch over the GB2.
"The HAP Stretch isn't a CF Para2 and if it ever did double in value it would take years and have to still be new in the box and what fun is that."
Nobody said it was a Para2 and you don't know how long it will take to double in value anymore than anyone else does. Fact is they may never double in value and could even go down in value. The only thing we can go by is what has historically happened with sprints in the past, and generally speaking, they have increased in value.
I don't even own a Hap40 Stretch yet and am unsure if I will get one. I have the ZDP189/BRG version. I like the color and steel and it cuts and does every thing I need it to do.
OP, if you are patient and wait till there are a lot of them in circulation, should eventually be able to score a GB2 for a good price. Shortly before they went discontinued I bought a basically NIB GB1 for $95 shipped. Amazing Taichung quality made Spyderco and well worth $95. Those kind of GB1 deals are next to impossible to find now that they've went discontinued.