If you read the thread on twitter after Garry's original tweet, he goes into more detail in response to peoples questions.
Basically Penrith were very interested, and so was Hunt in what they had to offer (at least hunts manager was). Penrith realised they couldn't offer the $$ that Hunt (hunts manager) wanted, so they pulled out of the race. Hence their statement (and presumably Goulds twitter post about the 3 bedroom house).
This is all part of a managers job.
The dragons have offered more money than the Broncos are willing to.
There is alot more to consider than just an extra (lets say) 150k per year. Uprooting a new family, general lifestyle, cost of living (buying a house in Sydney or Sydneys south?), will new team be a premiership contender (dragons? No), and even such things like, would leaving the broncos stunt personal brand, both during his footy career and post, and his ability to generate income from that in the future.