Chain prices and specificity

[Visitor Q]

As a habit ive picked up, i whack in cbr600 and cbr 600 into ebay every now and then, and i picked up this

https://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7962239222&ssPageName=ADME:X:ON:UK:2

Basically its a DID O-ring chain, alledgedly only for one type of bcr 600, and not a later model, hence hes selling it.
Call me old fashioned but surely thats down to the sprockets?

Also how much is this worth, before i go all bid crazy (i try and avoid the temptation). I bid up to 50 quid (well bid+p+p = 50) but its gone past that, so just wondering what it would be costing if i bought it in the shops new, when it was needed?
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