I'd easily pay $100 for a perpetual license for a client that has as many capabilities as TB, plus does exchange calendars/address books right. I'd expense it then, of course :) And it would be worth every cent - while TB has many excellent features, lack of some more enterprise-y things probably cost me much more than $100 in time and effort over my career.
The thing is, however, $100 paid to closed-source software vendor never guarantees he won't be out of business or bought by some Novell that will promptly run it into ground in a year or two. With open source chances for product survival are higher - though, as we see here, are in no way guaranteed.
Just in case anybody cares, I'm currently on Mac OS X, but when I worked on Linux & Windows, I used Thunderbird too, and the same applies for both of these OSes too.
That would seem to be the catch, I was originally talking about just an email client. This would now be an email client, exchange client, calendar, address book...
The fact is that calendaring uses email as exchange platform, and address book is directly related to emails, so one would expect naturally all of it to come to one place. Especially if we talking about business environment where all IT/organizational/business procedures expect it to be so traditionally.
The thing is, however, $100 paid to closed-source software vendor never guarantees he won't be out of business or bought by some Novell that will promptly run it into ground in a year or two. With open source chances for product survival are higher - though, as we see here, are in no way guaranteed.
Just in case anybody cares, I'm currently on Mac OS X, but when I worked on Linux & Windows, I used Thunderbird too, and the same applies for both of these OSes too.