Motability Operations don’t want to lose customers as the leases are very profitable. Obviously selling car to the customer at the end of the lease means it’s unlikely the customer will start a new lease.
I bought my Motability car mid-way through the lease. This was during a DLA – PIP review that resulted in me losing higher rate mobility. I was, therefore, no longer a potential customer. Not only was the price fair, but the grants team paid towards it (£1,000 I think).