Today I completed my collection. The first thing I did was collect all of the Pioneers. I already had a 28S (my first), but then wanted the 48/49 series. In addition, I have the 33S, some Voyagers (11C, 12C, 15C) and one from each of the other families. Looking back at the $5k I just dropped over the past few months!!, I think I would just collect two calculators from each family (or just one, depending on your budget). At first, I thought the 48GX was the be all - end all of calculators, but it's not. (I'd say the 49G+ is, actually.) So decide what you want to use professionally and what you want to collect. If you need a loaded 48GX to use at work or school, then get one. If you just want to collect, then I'd save the money and get just the 48S and 48G (and 49G+ since it's the latest and greatest). Then pick up one or two from each family. For instance...
Classics: HP35, HP65
Woodstocks: HP25, HP29C
Topcats: omit unless you're into the big stuff
Spice: HP33E, HP34C
Voyagers: HP12C, HP15C, HP16C (get the 15C for sure, but decide between the 16C and 12C)
Coconuts: HP41CV, HP41CX
Pioneers: 32SII, 42S (the 17BII, 21S, 22S, & 27S are great substitutes, depending on what you're into)
Champions: 28S,???
Charlemagnes: 48S, 48G
Other: 33S, 49G+
Functionality-wise, there's a great deal of overlap here, but when you throw in a business calc (17BII), statistics calc (21S), programmers cals (16C), RPL calcs (48G), LED models (34C), and the model that started it all (HP35), then you'll have a well-rounded collection. You may give more consideration to get something that also goes along with your profession (e.g., business, programming, science-only, math-only).
Price-wise, you're in the holiday shopping season, so prices on Ebay may be higher now. Mint versions of any of these older models will go for $250 - $400 on Ebay. Some of the guys here may give you a price break and sell for less if they're Ebay-boycotters, but then again, many selling here also make mention (in their ad) that they are also selling on Ebay, so it does you no good since you're now getting into bidding wars. A mint 29C just sold for about $357 or so on Ebay, and a brand new 15C sold for over $400, but a very nice 15C can be had for $150-$225 usually.
Oh yeah, one more thing. I mentioned I just got all of the Pioneers. That's cool. But looking back, getting one or two from each family is even more cool. All from one family is boring, really. Also, don't feel like you have to get the very best model from each family. They sell for twice as much! You won't use them every day, anyway! Don't be afraid to get the "lesser" models and give them a nice home. For instance, I just passed that beautiful 29C (selling for $357 or so) and got a mint HP25 for only $73. I also got a mint 33E. I found a new 41CV,...didn't need the more popular 41CX. A 48G will do fine,... don't need a 48GX! A 49G+ is far better than the GX anyway.
