resale is low when you swap an engine. the car that you have in mind is a gamble. merc may even get you the same price regardless of the engine swap.
it is a good car. i encourage you to go for it. if the owner had told me about the swap up front, i would have surely bought it. its just that i checked it myself when he brought the papers after the deal was sealed. i felt bad as it came as a surprise for me and just left without paying him. dont forget to take the original lights.