I post on another Mums' forum, where the posters are all quite normal, and certainly not loaded, and I remember a thread on there about exactly this sort of thing. I was completely
My birthday is a week before Christmas, and I coped perfectly well as a child, having both at the same time of year. And in fact, I loved that time of year, as there was so much going on.
My parents, who certainly weren't loaded with cash, made absolutely sure that I had a very separate birthday, with no joint presents, etc. Also, that time of year is summer where I come from, which just added to it for me.
If you want to have a summer party, have a summer party! It doesn't need to be a second birthday, and children definitely don't need even more stuff!!
To be honest, I think ensuring children have as much fuss made of them, and as many presents bought for them as possible is probably more common than we think...