Wow thats certainly not cheap. I suppose even though we have a small population, we have far more people enjoying the outdoor lifestyle so more demand on these such items. Both my epirb and plb have 10 year battery ( 20 really ).Jon, you are lucky in Aus if you can get a new PLB for £100 and 10yr battery life. The cheapest PLBs in the UK tend to be around £220 upwards and have a 5/6year battery life stated on the products. I have 2 and have just had 1 serviced / battery replaced which had to be at a designated ACR service centre. So a 10 year cost of £35 per year but its very cheap at the price for being found should it be necessary!
Here they have to registered at Falmouth Coastguard who would co-ordinate any response to a UK beacon regardless of location.