It seems to me that there is NO reason not to buy 1.0. It's extremely useful as it is, and will be revved to 2.0 for free in a relatively short time--a few months??
I'm not sure whether the beta is open to everyone, but if you're techie, and you can get your hands on the 2.0 beta 5, you can run both at the same time. 2.0 has such fabulous new features as audio pronunciation, much more powerful flashcards, a built-in document reader, a link between PD and other programs, e.g. word processors and other readers, more flexible input methods, among others.
I envy the thrill you're going to have the first few months you use either 1.0 or 2.0. I don't think I'd be as far along in my studies if I were still using paper dictionaries with or without some other brands' Chinese dictionary.
Sandra