I'm aware the magmotors are as good as new but the price your asking comes very close to a brand new unused one without any of the benefits. 400usd (for a new one) equals 236pounds.

I often buy and sell secondhand materials and items and you'll be lucky to get 70% of the value of a new one.
Perhaps someone here is willing to pay close to your price but in my opinion your overcharging.

No offence but you should be realistic.