Five seconds before you sign the contract for any of these big commercial packages you should demand free on-site training for one week about a month after installation of the package. And with all these packages, a user course is really needed because the programs provide hundreds of options, which are not always easy to find or easy to understand. You simply cannot afford to pay for a course given by one of the companies. Amateur courses are normally free, and have the additional benefit that the teachers are usually experienced molecular scientists, and not sales managers turned teacher. Software companies make you pay for ever.
Amateurs normally request a symbolic fee, and give free updates for ever.
Don't buy from amateurs who rely on a single post-doc or PhD student, unless you want to use the program for just one application. Another question is the work you want to do. Buy whatever Alwyn Jones advises you to buy, and get everything set up for your work. If drug design is your main goal in life, we would strongly advise you to obtain Sybyl. Don't buy its protein module, because it was state of the art software in 1988, but all of the other modules I ever worked with are good.