@jfm, good sensible advice from macdesigner. Thought iMight chime in to save you the time and £'s getting your S1 from the US over to the UK.
Bottom line (yes) mostly likely find a good deal from an authorized Cervelo dealership in the US especially on the '09 (if you like the colours) and but here's the catch -> UK customs excise will hit you with 15% import duty fee and not to forget an extra 15% for the VAT which incidentally will shoot up to 17.5% in Jan 2010. So we are talking adding 30% on top of the actual cost of the bike shown on the purchase invoice. Ouch!
Summary - 30% charge until the end of 2009 and 32.5% charge from Jan 2010. This applies to both "USED" or brandnew bikes! Unless you are going to be there on holiday in the US/Canada, you could ride the bike, get it dirty and bring it back with you on the plane (which I did many years ago on a different brand) then you could get away with it but not suggesting it will be 100% full-proof.
And if I have done my homework thoroughly, even with the best deals out there in the US/Canada, it will not save you money importing; it will end up costing loads more. If you are really lucky to find rock bottom deals in the US/Canada, you might just about breakeven by bringing it over. If I were in your shoes, I would save the hassle and just explore options with your local Cervelo dealership so you can get that expertise of building and working with Cervelo bikes.
One other option is importing a 'frame set only' should work out to be slightly more cost effective than a complete bike, especially if you have components and gruppos and bits and pieces you can transfer over from your existing bike or pick these up relatively cheap by browsing online and build your Cervelo up that way. With the latter unless you know and have experience of building a Cervelo, best to have it build up properly by your LBS who has loads of Cervelo experience. They should be able to build it up for you for a tidy sum of £120-£140 depending on the shop. If you buy bits and pieces from them, they might even throw in the bikefit for free which is worth getting when you are spending this amount of £. I'm not talking just about the frame size, get them to set the bike up to suit your riding style, goals/objectives, technical adjustments, body flexibility so you get the optimum performance from your S1.
Check out R&A Cycles in NYC !!! They still have 2009 S1 frameset in stock for in a 51cm for US $1200 (£750??) so you might want to explore that option and do the maths to see if it makes sense or not bringing it over when you compare the prices at Primera Bournemouth and The TriStore in Eastbourne (not sure where you are in the UK, but these might be a good starting point). You could also try Sigma Sports in Kingston-Up-on-Thames, but they are pricey and not that great customer service so I would give Sigma a miss. If you are near Finchley, NW London Bike and Run is good.
But best of the bunch
DeVere Cycles south of the river in Streatham, London definitely worth a visit (talk to Paul the mechanic - top
bloke!) or the owner Maurice (ex-Pro rider!!!) who knows his bikes
inside and out. Don8t forget to have a play with their online 'bikebuilder
tool' so you can tweak various options and components to your liking
until the cows come home :) and very competitive pricing. Have fun,
iDid!
Let me know how you get on with Devere. iThink they offer a very good service and have a wealth of expertise, friendly and good all round customer care) especially from Paul and the Owner himself who will look after you until you are satisfied. Hope this info helps and hApPy S1 hunting!
oh and btw - - - and if you come across a 51cm jet black anodized frame (2006) be sure to let Rock know rightaway!