The mileage, I can see the issue, but only as a resale issue, in reality it will make sod all difference to the car. Not being a GT is a bonus me things these days, as the benefits are not worth the money and aftermarket products are far better suited. Heated seats, nice if you want piles, cruize contol good for average speed camera areas.
I think that this will sell, bit at £15.5 - £16 max, i'm not saying thats right, but that what I think it will fetch