Some are shareware or demos of the full version. If you're curious to see what's out there, this site is a great place to start. Going online isn't the only place to start your software research. You can try the more traditional approach of going to trade shows, word of mouth or just browsing store shelves. Going to a trade show allows you to view the software in action, discuss it with a company representative and collect information.
Word of mouth is a great way to find out about a product.
If you've heard great things you are more apt to buy that product. However, before jumping in headfirst and buying that software package, make sure it is really what your company needs. It may be right for some and not for others. Lastly, you can go to your favorite computer store. Browsing the shelves and speaking with salesperson is sometimes what you need to make that final decision.