Usually I’m not such a big fan of “shareware” products and the like – too often you get charged for crap that is outclassed by the free alternatives. Plus, I didn’t had good experiences with the “customer support” of independent vendors in the past.
That said, there are some tools that are really worth their price, like TextMate. And a while ago I bought 1password (1passwd before…), because I wanted to share my web passwords between all browsers (and Firefox doesn’t support the Mac keychain). It worked as advertised, giving something like a “single-sign-on” from any browser. Also, with the built-in password generator I don’t use the same default password for all sites any more. It also synchronises to the iPhone/iPod touch (and also with a Palm device, if you pay a little extra).
And I can finally log in to password-protected sites on the go.