How do you do this friendship thing for an 8-year old? PART 2

Hi Ladies - last year, I posted about the tough time my 8-year-old son has had with making friends outside of school. Shortly after my post, my son did make a very good friend who lived around the corner. I was so happy he finally made a good friend in the neighborhood, and they spent the year running back and forth to each other's houses having a blast. It was wonderful watching them bond. But sadly, without much notice, his friend's family got transferred across the country, and just like that, he was gone. This happened just after school ended, so it's been a tough Summer for my son missing his good friend, and for me too. I can't believe how upset I am about his friend moving. My son is so lonely, and it's been heartbreaking. So to fill the void, I've had his "best friend" from school over to our house a few times this Summer. His mom asked my son to come over one time the entire Summer. I've had a couple other friends over too, but again, none have asked my son to come over to theirs. He has many friends when he's at school, but none of these friendships exist outside of school. If I had not set up playdates with his "best friend" this Summer, I am certain we never would have heard from him. And none of his other friends have reached out either. I am tired of having all these kids over to our house, and not even have one playdate reciprocated. He's going to be in 3rd Grade, and since Kindergarten, he's probably had less than 10 playdates at someone else's house (excluding this good friend who recently moved). Please tell me - is this normal? I don't feel like it is. And in case you're wondering - my son is not perfect, but most people praise him for being such a nice boy, good manners, well-behaved. He is well-liked by peers at school, gets invited to many birthday parties. But all he wants is to get invited to someone else's house occasionally. I do feel part of the problem is where we live - we're in an upper middle class area, I hate to say it but I've never met more snobs in my life. He has lots of classmates who live in our neighborhood, but the parent's aren't very friendly, and my son isn't really friends with those kids at school. One of them sits next to him on the bus and stomps on my son's new shoes... as an example, so I'm not going to encourage relationships with kids like that... I don't know, just venting I guess. And praying he is able to bond with someone this year at school. Please tell me it gets better when they get older!