Offroad Tyre and Alloy Option for GU Patrol

Having gone through the situation where we need good quality low k tyres for our travels in the outback I am wondering whether the option of a complete set of wheels for offroad is the way to go! If your highway tyres are getting down and you feel a need for something with a bit more rubber you are basically in a position where you must toss your old rubber. When you return home to the land of freeways and sealed roads the ATs, STs or whatever you choose are in some ways unsuitable for that job also. They are also quite noisy. Maybe the ideal solution is two sets of wheels but can the expense be justified. On the plus side you will have tyres designed for the job and you will be able to use them until they are worn out rather than change as your circumstances dictate ( i.e. blacktop or dirt ). The down side is the cost of the exercise and the fact that I've been told I can't put 5 offroad wheels in the spare room. Has anybody had experience with this process and if so, your thoughts please? PS: I made some inquiries this morning and several tyre dealers quoted me about $2500.00 for 5 x ROH Monsoons and Cooper STs or Bridgestones, Pirellis or Good Years. I was quoted $350.00 for BF Goodrich Ats, sounds a bit steep to me! Your comments would be appreciated.