Kids birthday parties, A joyous occasion, or a test in strength of character?

We are now on the downhill stretch to G's 5th birthday. His first birthday where he has had school friends to invite, or in our case - not invite.
Poor G has been left out of about 70% of the birthday parties so far this year, and Ive seen how upset he has become over it so I endeavoured to spare other kids of this pain. Although even as I'm typing this I wonder why I bothered - other parents didn't take my sons feelings into consideration, why should I go so far out of my way to protect others.

Last night G and I sat down and wrote out the invites. I am super dooper proud of him, he wrote the guests name and his name on EVERY invite! First time too, no practice runs! All were legible too, well 4yr old legible handwriting anyway!

We put them into plain white envelopes so that when we put the few ones into the communication pockets at school, they just looked like normal school stuff.

The other invites have all been just the invite itself, placed into the pocket, so it stood out clearly which kids were invited, and which were not. Ok, maybe it just stood out to me because G rarely gets invited!

Its crazy when I think about it. A 10 kid party doesn't actually stretch out that far. Once you take out the birthday boy and his brother and 3 family friends, it only leaves 5 kids from school. How do these other parents afford to invite 10-15 of the class?! We'll be scrimping to pull his off!

The expense of birthday parties is a hidden one. I was thinking about having one at home or the park, to save some money, but once you factor in food, party bags, decoration your up already $50 - $100. Not to mention providing entertainment too! G's Hungry Jacks party is all inclusive (bar the cake, which I'm hoping a dear friend of mine will make, or I will), and only costs just a touch under $70 for the 10 kids - and whats best...? I don't have to entertain them, keep a hawk eye on them or clean up after! The last one is probably worth $70 by itself!

G has already learnt that you cant be invited to every party. I'm hoping he remembers that this by no reflection on him. So I pray the other children realise this too.