I have something like this at home: http://www.amazon.com/Apex-TDH14-1-Threaded-Dumbbell-Handles/dp/B000ASB66E/ref=sr_1_38?ie=UTF8&qid=1312425497&sr=8-38
I inherited my father's weights so I have a lot of plates that I can add to those dumbbell handles. I can also go and purchase more plates in the future no problem. Craigslist usually has amazing deals on stuff like that.
If you can find a good deal on an all-in-one adjustable dumbbell set then, by all means, feel free to make the investment. If you can find a bunch of plates on the cheap here and there you might want to just get the adjustable handles and load them up over time.
You could go the dumbbell handle route and then use real plates on them... http://www.amazon.com/Marcy-TDH14-1-Threaded-Dumbbell-Handles/dp/B000ASB66E. .. But they can be unwieldy.
Ive had a set of the bowflexes for years and they are as solid as the first day. I think the issue is that if you drop them, there are plastic parts that can break. I just make sure to treat them carefully.
For that, all you will really need is dumbbell handles and/or a standard barbell and some standard plates (NOT Olympic plates unless you buy an Olympic bar). The best place to get them is on craigslist or a 2nd hand sports store.
Dear god man! All you needed was these and some plates bought off of Craigslist for ten cents on the dollar! If you can, return that overpriced shit ASAP!