Not the cheapest price but a great router and sold by Amazon AU.
On another note, does anyone know where I can get an extender RBS50?
I feel it's almost worthwhile getting a second RBK50 set just so I can use the added extender and sell the router unit.
LOL well there was the deal on Friday…
https://www.ozbargain.com.au/node/585150
Although that's UK version. I'd be tempted to do the same as what you were suggesting and grab this to split the set, butI'm not sure how much you'd get just for the router. Don't think it's worth it and don't want to be stuck with the router if I can't find a buyer.