Sure they can afford it. How much does it cost to burn a setup CD $.50, $1.00 maybe? Then maybe a couple bucks for the box. Say they give away 1000 copies, and it cost them $10.00 (I am sure closer to maybe $5). That is $10,000 dollars. Now only 1% (10) of those initial 1000 user would need to purchase additional licenses, or re-new the next year for them to make there money back (assuming the pro version). What better advertising could you possibly buy then that?
Hell that doesn;t even account for tax benefits they may get from giving away their product.
And that's why Autodesk originally liked the fact that AutoCAD was being pirated. It become the defacto choice because so many people were used to it. HMMM. Alibre floods the market with free software then reaps in the maintenance funds. Those guys are shrewd, very shrewd.