Eddie
My logic on bidding on the bike:
a) I'm assuming that when it comes to a folding bike for your wife, you want to purchase a crank motor bike and that if you had to pay £1600 for the BH from one of the UK suppliers, that would not put you off the bike.
b) What is the wording on the BH Emotion European warranty?
c) BH seem to specialise in the more expensive end of the "push" bike market, assuming there is a link between the push and power operations, would they risk their reputation on inferior power products?
d) It appears to me the Panasonic unit is for the UK the most "common" unit available and probably also one of the most reliable.
e) The only expensive items on the bike that could fail (other than frame/folding mechanism) are either the motor / controller / battery. Everything else can be sourced at reasonable cost from the internet.
f) What is the availability of spares /rebuild / used / refurbished for Panasonic mechanics - we know the cost of batteries.
g) Based on forum experience what is the likelihood of failure - what are the potential costs that you might be left with if the warranty is not honoured - consider also any consumer rights, is this a trade seller?.
h) If the potential risk of repair costs exceed the differential between what the auction price is, and what you want to spend on a folding bike for your wife, can I recommend you search eBay for the proverbial "barge pole".
Good luck with your decision making
Mike