This is commonly asked, the 'original' stuff in the clear bottle called simply Klear is no longer available, any that you see about is 'new old stock', buy it, it won't be replaced once it's gone and the stuff saves for years. This is precisely why it's £10 a bottle online, people who have cottoned onto it's use in the modelling world have bought up old stock at £3 a bottle and are now making a killing on it.
I would love to find a handful of bottles of the old Klear to stockpile.
Several mainstreet supermarkets now sell Pledge, (with Klear shine) in a similar shape bottle but white, the contents are a milky colour but it does seem to work like the old stuff, and it's £3 ish a bottle, the only thing i've not yet ascertained is if it dissolves in itself like original Klear did.
I got the new bottle from Morrisons BTW