No its not an example really.
You are comparing the economy of a 300 million + person country to one of a 30million country...
Dastek is the company that makes the unichip. Every other region of the world has a unichip distributor, then there are dealers like you went to.
Like any business, you buy in bulk you save. Imagine how many Unichip's, unichip usa buys off dastek each year, then compare it to Unichip australia.
All that aside, there are extremely strict contracts in place to keep each region of the world seperated to take this economy difference into account. If a company in the usa is caught selling to australia or anywhere else in the world and abusing its massive buying power advantage it is automatically stripped of its licence and will never sell another unichip again.
As for your boost controller. Pumping more boost into a diesel simply causes it to run leaner which is fantastic for the engine as it will run cooler and more efficient.
However the power comes from pumping more fuel in to match this higher boost level.
So, once you fit a boost controller you would have to get it retuned to suit the higher boost level..
I reckon if you go back asking to get it done you will probably be told its a waste of time and no good for the engine, causes excessive backpressure etc and that you should spend $2000 on one of their intercoolers instead. All a load of cods wallop really Maybe if you lifted it to 25psi those things would start to come into play...
The truth is, it is worth it and you will make significantly more power and it will do your engine a favour by lifting it 3-5psi over what its running now.
Humour me and give it a try, call them and ask if they would touch the tune up for free to suit a boost controller if you refitted it. After all it only spent 15mins on the dyno when it was fitted right? Whats another 15mins.