@grimjaw89
Post whatever demand you're comfortable with. It is your item and you are entitled to set its price. Don't bow to the pressure like a few others here who sold their 1080Tis for ~70k (and are now probably regretting their decision).
A few 1080Tis were on sale in the US in an EVGA B-stock sale the other day and went out of sale in an hour at 650USD.