Yes, a successful price is what the market will bear but I fail to see the relevance of that in this discussion. Simply, Ballinger gives more for your buck - that was my response to your query as to why Adelaide would ever want to replace one blue-collar import with another. Remember that they would've kept Dusty at the right price, they just needed to get cash from somewhere to upgrade Rees to a starting centre.
I've already said plainly that Oscar didn't leave because he was offered more money. If he was about money, he wouldn't have taken a large paycut (can't remember specifics, but 20-30%?) previously in order to get Dusty into the team at all (no one else was sticking their hand up).
You're right that these departures don't necessarily send positive messages to targets, but I think that potential players would recognise that other teams are simply putting more value in our players. The offers to Holmes and Forman wouldn't have been (don't know Holmes' specifics, but would have a rough idea) or weren't (Oscar's case) offensively low.
You're right that they should still manage to put together a competitive team.