I don't really care if the desktop gets snatched. I'm more worried about old tax returns, the credentials stored in its password manager, etc. Breaking in twice (once to install a bump in the wire key logger, and once to walk away with the machine) would lead to at least 10x more payout for a burglar.
Also, ignoring what it is worth to the attacker, having to roll over all my credentials, freeze accounts, etc, etc, because my desktop was stolen would cost way more of my time than buying a new desktop (happily, the drive is encrypted).