It's worrying that you should even need to ask this question after 18 years as a member. One glance at eBay's money back guarantee would have shown you that to qualify for eBay's money back guarantee you must pay through eBay's checkout, using PayPal or PayPal Credit, a credit card, debit card, Google Pay or Apple Pay. Bank transfer would NOT qualify.
Even with eBay's guarantee, buying anything of this value on eBay can be seriously risky, so please be careful and think about what you're doing.
I take it you realise that import duty, VAT and a handling charge will be payable on delivery in the UK? Don't even think about not paying it, or you may forfeit any right to a refund.
If the item fails to arrive you should be able to claim under the guarantee - but be aware that eBay goes solely by the tracking record. Parcels are often left on the doorstep where they can be lost or stolen, or can be delivered to the wrong address. If the tracking record states it was correctly delivered eBay will not require the seller to refund you. We often hear from buyers who have experienced this. This is a significant risk for a $10k item.
If the item arrives damaged or not as described, you will almost certainly have to return it to Australia at your own cost and risk to get a refund, and provide tracking proof of delivery to the seller's address. You will also have the hassle of trying to reclaim your import duty and VAT from HMRC. A possible worry is Australia's absurdly strict rules about what can be imported - it's possible that something that was allowed for export may not be permitted for import. Check beforehand, as if it's seized and destroyed bang would go your $10k.
As I said, do please think about it. I wouldn't even consider taking the risk for an item of this value.
