In my opinion, it is unethical to illegally obtain the Sierra games if it is possible to get them legally.
Case in point, a couple of years ago when I discovered eBay, I bought
every single Sierra talkie/CD game. Most of the games I obtained
were brand new disc-only releases or compilations (only 3 were
second-hand) – the cheapest cost me $5 U.S. and the most expensive was
$10 U.S (plus shipping – I live in New Zealand).
I’d imagine it is still pretty similar on eBay, so I don’t see why
anyone would have the need to pirate these games. I don’t see a
distinction between whether or not the original publisher is selling
them still or someone is on-selling them.
If someone is legitimately replacing a file in a bought version of a
game then I think it is ethical to copy that, as it is not likely that
Sierra/VU would be able to replace it for them. Again, I think
patches/fixes come under this as well.
The only thing I see as unethical is people who use excuses to pirate
the games when they are still readily available dirt-cheap on trading
sights and in bargain bins around the world. In this age, no
excuse is good enough – especially with the cost of shipping a CD being
so little.
Some may argue that the original developers are not going to see any
revenue from these games, so it is ‘ethical’ to steal them, but thats a
pretty lame excuse, as they wouldn’t have seen any money on a $5 game
sale anyway.