Friends- showing your appreciation ?

During self-isolation, a good friend has been helping me with yard projects. I know I'm saving money because landscapers can get expensive, but he gets "offended" when I try to compensate him for his time. He tells me that he's happy to be out away from his wife and teenage son, but I feel bad for the cheap labor. I've been buying lunch and gifting him with $100 gift cards that he's "accpeted".

Today we removed bushes, dug out grass and laid stone for an area about 128sqft. Took about  4 hours and I'm wondering if a 50$ gift card to his favorite clothing store would be good to give him.