I think Spike was going to sell the wine kit because he would probably be moving into a much smaller apartment and wouldn't have the space to hang on to all that stuff. He probably figured he wasn't ever going to use it and so he'd better sell it, but obviously it still had a lot of sentimental value for him because it held some dear memories of his father. I loved that the team picked up on that and made sure Spike didn't sell it after all.