Good luck on your friends lowball. Being insulted by a lowball is kinda ridiculous. This is business. You either take it or you don’t. No need to get all emotional about it.
Assuming that 450K is accurate and fair market value, then their pricing it at 430K should easily sell in any market. If they are in distress, they may consider your offer. Otherwise they shouldn’t need your friend.
If they are just trying to overprice it, then yo friend may have a high chance.
Wait.. your friend is buying at 10% off in SD? Are we not in the “everything is going to crash 30-50% forum”? Did you warn him?