I generally take the 'self-insured' route, ie I do not pay the reduce the excess at least in Australia.
Having to fork out $2,000 would be highly annoying, but it would not break the bank. I've saved loads of money over a long period by not taking the excess reduction option.
The major car rental companies (Hertz, Avis etc) in Australia are quite good IMHO. You can reserve a car without leaving credit card info or a deposit. You can cancel it any any time without penalty. You can shorten or extend your rental without penalty. Car upgrades are the norm, rather than the exception. They don't make you pay for stone chips or minor scratches that do not require a new paint job or trip to the panel beater.

Someone up there mentioned kangaroos. I work for an insurance company, and I'm constantly lodging claims for kangaroos and other animals. They do huge amounts of damage, and as with any claim, if you have no one to recover the cost of damages from you will have to pay the excess. Also bare in mind that if you have an accident with someone you may need to obtain the name, address, phone number, license number and registration details of the other driver to have your excess waived. If any of these details are missing they can make you pay the excess regardless of who's fault it was.

Which also bring up an important point. Avoid driving at dawn, dusk or night in country areas, except on big, big highways.
It's just too likely that you will hit a 'roo otherwise.

I'm with #12 on this one. I've never paid the extortionate $20 or more per day excess reduction. I haven't had a crash in yonks. In fact the only decent crashes I've had were on motorbikes over 30 years ago. I've never done more than a few hundred dollars damage doing things like backing into bollards or putting a towbar through my front bumper when a stupid munter (I do like that word) decided to stop half way through a right turn when the traffic lights went orange.
But I digress. If I prang a rental car, I'll suck it up and pay the $2,000 -$3,500 excess. It'll hurt but it's not TEOTWAWKI.

Thanks everyone.
I'll probably won't be driving anywhere too remote, idea is to go Sydney-Blue Mountains-Hunter Valley- TBC- Byron, so hopefully roads shouldn't be too bad, but that said, I think I 'm gonna go with paying the liability reduction (which means the wicked camper!). Don't like paying the fee as it seems a bit of a rip off, but I really can't afford to blow $2K if I do end up in prang.
Oh, and #15, whats TEOTWAWKI?

> but I really can't afford to blow $2K if I do end up in prang
Yes, that's a good philosophy to live by. If something is going to break the bank, protect your self against it. If not, forgo the insurance. That said, even if $2,000 is not TEOTWAWKI (I love it!), if I was driving say Melbourne-Wilsons Prom both ways at night in a renter, I'd pay the extra insurance as it is too likely to hit a 'roo.