A better way is to agree to:
Buyer pays for pre-buy and annual.
- Any airworthiness items, Buyer pays for first $1,000 of repairs, Seller and Buyer split $1,001-3000, Seller responsible for everything over $3000.
- If seller declines to pay for their shares of the repairs, Buyer can walk.
- If more than $3000 in repairs required, Buyer can walk.
- If Buyer Walks, and plane is in Annual, then Seller agrees to reimburse for the Annual.
Or some version of the above, so that both parties are invested in the inspection, and, the Seller knows you are trying to buy the plane (paying for the Annual and the first $1,000) and only negotiating if the plane is less than advertised, or major items discovered.
As I said, 'one way to skin the cat..' is the way I suggested, there are certainly others.
I don't know why I would want to be 'invested' in fixing the hidden defects the seller was trying to sneak past me but hey, if it makes you feel better that way, sure you can do that.
If it's a true firesale price, buying as-is and assume the worst is certainly a good option for an informed buyer. A cherokee 10k below retail for a plane that hasn't been looked at in 2.5 years is not a firesale price.