Different manufacturing process... these are rotocast toys, and the BMF's a multi-part injection molded toy. Rotocasting's cheap but simplified... Like a pink flamingo is rotocast generally. The BMF's complex, electronic, labor-intensive, etc.
I'd assume they see this as something they can roll out again for the films as well... It's of an iconic (a true use of that word, not a "collector" use of it where we think everything's iconic, haha) ship, simple to make, large and "impressive" to look at, not absurdly heavy.
$60 isn't cheap to me either and I'd be picky on what I spent that on... But compared to the ever-inflating price of the BMF? If I had to guess why they didn't go smaller, it's that they want something visually impressive but still moderately affordable and more likely to sell than something $100 and well beyond. *shrugs*
That's my guess anyway. I'm sure many of these choices are to meet demands from retailers as well. We suffer from that stuff too.
I wouldn't doubt that we'll see these ships, or at least the Falcon, again soon... Same as that giant Vader from Jakks Pacific. I can't imagine that won't be returning despite collector's opinions on it. It's a big, goofy, "wow fact" thing, at a lower price.
I'm not personally interested in this Falcon, but I am pretty sure they don't care if I am either.