I'll just start by saying what has been said time and again on this topic, and it should be the motto of collecting, as well as anytime something seems too good to be true: Caveat Emptor...let the buyer beware. Most of us have, at one point or another, fallen victim to an unscrupulous seller.
That being said, the Shadow Bob Head, is, in my opinion, one of the most iconic (pardon the pun) and recognizable items from what many would call Oakley's heyday. For them to be reproduced is acceptable to me, especially since I know how fragile they are, and I can only guess how low of a percentage of the originals are still around. It's acceptable, that is, just so long as they are sold and bought as such. It should be clearly explained that it is not an original piece. That being said, I have two of the originals, and both arrived shattered due to poor packing from the store that transferred them. Fortunately, they were in two separate boxes, so I was able to know which parts went to which Bob. I have painstakingly rebuilt and repaired them, and you'd never guess that they were damaged unless you look inside them, but if I were to decide to part with them I would clearly explain that they were damaged and repaired. It's called being an honest seller.
As a side note, I have no earthly idea why they were made of plaster and not blow molded in plastic, but I digress.
The spike head, or Crystal Bob, is another piece that is in high demand, and if someone has the skill and equipment to reproduce it, fine, but be honest about it. The paint jobs on a lot of them have been pretty badass, honestly.
The trophies are another thing entirely to me. When I worked for Oakley and they started handing them out at Retail Assault and Sales Meetings, those trophies were hand made, hand painted, etc, which made the achievement for which they were given that much more special. The athlete trophies were also hand made from what I understand. For the trophies to start being reproduced cheapens the achievement for which they were originally earned in my opinion. The fact that there are reproductions theoretically means that someone who earned one either made a mold themselves, or in one way or another turned it over to someone who did, and that's just not cool.