The buyer already attempted to negotiate the price of an element they already
received but failed to mention anything about the price of the element when they
made the purchase, only doing so just before receiving the refund for the missing
part. Buyer is also asking for a refund of $10 for the parts they felt were over
priced vs the market on top of sending them the correct torso they were already
refunded for.
If they chose to buy at a price above average, they should not later complain
your price was above average.