Having had an R56 Cooper S and now an F56 Cooper S, I would avoid the R56 which ran until 2014 particularly one with a high mileage. Mine was on its third timing chain when I sold it. I got rid of it because every time it went to the local dealer the bill was around £1000 which was ridiculous particularly as it had only done about 50,000 miles. I think the F56 is much improved but is obviously a bit more money.

The replacement engine has done 40,000 miles so although the car is high mileage, the engine isn't.
I'm told by another owner, that the timing chain issue has been addressed by some recall/modification?

I'm betting it's the turbo engine not the sc engine so yes that would put me off it unless it was much much cheaper than any others out there and there are known big issues with those engines losing their top end timing due to a stupid pulley design on the head. Save some money and got for an sc engined version that's older and have less issues with it IMO FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.

FYI it's due to the cam sprocket have two different parts so over time can and does slip as they can't be totally locked together to avoid this.

A company near me does refurb engines for this very issue when it all goes wrong and when I drive past they always have a queue of minis outside waiting for engine transplants. Go for an R53 jcw and stick the saved money to one side for any tweaks and normal repairs/servicing 👍 FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.

We have an R53 - a lowly Cooper S convertible rather than a JCW - I was thinking of changing it for a newer one, but may think again now - only done 46k and cost me hardly anything in maintenance.

Still got my r53 cooper s works which has been remapped loads of fun to drive and still in the mini size not the big minis which to me take away the point of having mini ,The engine on the one your looking at may of been replaced but the drivers seat and everything else will of been worn so personally i wouldn't buy it L322 2008 vogue
R53 Cooper S Works tuned beyond the works SOLD
R33 Nissan Skyline in rebuild 400bhp atw

On the timing chain, since the third chain tensioner was replaced we haven't had a problem. As stated above, it was a badly designed part which was redesigned, so providing you keep the oil topped up, shouldn't have problems (touch wood.....)

JCWs of the age you're looking at should come well specced, so leather, sat nav, a/c, decent hifi and phone integration should all be there. Heated screen is part of the 'vision pack' so would have beeen a costly option. Its the only one ours doesn't have, the original owner went nuts, we've even got a TV/DVD player FFS!

I have no opinion either way but I'm wondering who in their right mind would do 35,000 miles a year in a glorified go-kart!

 Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

The timing chain issues on the r56 cooper s were on the n14 engine which ran from late 2006 till 2010 for the standard cooper s. The JCW ones took the new engine, the n18, later maybe around 2012. The N14 engine also coked up really badly and needed walnut blasting to clean it out. The N14 engine was French I think, they used it in the Citroen ds3 and the Peugeot 208 GTI. If this is the n14 engine version I would stay well clear even though its new, an N18 one should be much better and more reliable.