Hiya Ben
I notice that the seller has limited feedback dating to 2005. Not that this is necessarily a bad thing but I'd ask him if Cash on collection was a possibility, just to put your mind at ease.
The Ric is great in that colour isn't it Some more pictures would be good, and you could ask for them. Also does it come with a Ric case and is the 'case candy' all there too? He doesn't say whether or not the bass has the Vintage Tone Control fitted. Probably not I suspect. If you like the Chris Squire sound I'd strongly recommend retro fitting it. It put a capacitor across the bridge pickup pot and gives a more vintage tone at the expense of some output level. It's switchable therefore reversable.
I expect the price will rise considerably.
Have you tried a Ric before?
Good luck