Doug, IMHO if you can get it inexpensively, and would like a fairly unique 9mm handgun for your collection, go for it.
They are never going to reach the value of the other Detonics guns, but they do have their own place in history, and I always get curious people asking questions at the range. I didn't buy it as an investment piece, and know it may never go up in value, but thats ok.
I got mine w/ a box, manual, spare mag and a minuteman pancake holster for $300. Got it a bit cheaper than the $400 they had on it because the grips were cracked. I won't even go into the ordeal reguarding the grips! LOL

Since then, I have met many people online who own them and it's fun seeing this fairly uncommon gun being used still today. I've talked with at least one State Police officer who uses one today as a backup gun, as well as a minister who uses one as a concealed carry gun.

I have 5 9mm handguns, and none of them are 'mainstream' pistols. No plastic guns, no flavor of the month pieces, just an eclectic collection of guns that have caught my attention over the years. The Pocket 9s are what they are, like detonics collector said, some love them, most hate them, but thats what makes our hobby fun.
I personally can't even think about buying any of the 'modern' type guns, but like my guns made from steel, and preferrably milled. I'm currently trying to save some cash for a Detonics 45, and would buy a Detonics over a Kimber any day. :)
Why? Nothing I can put into words other than 'feel'. I've handled a couple of Detonics combatmasters, and handled Kimbers and many other 1911 clones, and of the compact 45s, nothing seems to feel better in my hand than the Detonics pieces. But, I'm going off-track here...

Only you can decide if you want it. If you do, buy it and have fun with it!