just deciding how to hide the bill for such an item myself
A few steps to persuade the boss -
Say to her it's essential work for the car - possible mot failure next time round.
Get a quote from your local Seat dealer for supply and fit of original equipment (no need here to pretend you're surprised or shocked at the price!!!!!).
Say you can get "similar" parts and fit them yourself much cheaper than Seat, therefore saving money.
Job's a good 'un