Kids Birthday Parties- How Far is Too Far?

As a working mum, I am often plagued with guilt. I know MM enjoys going to daycare and has loads of friends and spends the day doing activities that stimulates his little mind and excites his senses. In fact on the weekends he often asks if it is time to go to daycare yet etc. That doesn't stop me from letting the dark place in my mind run riot sometimes and convince me that I am a bad mommy for going to work.
So instead of ignoring that particular inner dialogue, I try to prove myself wrong by doing some overly "domestic" type things. One of these is his birthday cakes. For some reason I have convinced myself that a 'good mother' makes the birthday cake and it can't just be a normal cake - it must be a master piece.
On MM's first birthday I thought it would be a good idea to make him a cookie monster cake - 3D of course. the problem with that was that I had never actually made any kind of 3D cake before and I left it to the day of the party. BIG mistake. Friends of ours had an engagement party the night before and it was one of the first times in the year since I had given birth to MM that I went out and really let my hair down. I wasn't really that used to it and the next day I felt awful. Seriously like a*se. I was committed though and by the time of the birthday party cookie monster was the 'guest of honour' and everyone was amazed. MM didn't know any different and would have gladly devoured any cake that was put in front of him.
Fast forward another 12 months (feels like yesterday, just quietly) and MM is turning 2. He is Thomas (the tank) crazy and I feel compelled (seriously it was obsessive) to make a 3D Thomas the tank engine cake. It was a big success but took hours - I slaved over that thing. MM was suitably impressed but it was fleeting and I was actually a little devestated to have to cut into him and slice him up (Thomas obviously- not MM). I swore then that this weird cake thing that I was doing would have to stop.
It is that time of year again and now MM is turning three. I asked him the other day what kind of cake he wanted for his birthday- thinking I was going to get an answer along the lines of "chocolate cake". He said "a Cars cake". He is Cars2 mad. The guilt took over again and I gave in and said 'of course you can have a Cars cake'. I thought back to the promise I made myself the year before and set out to find someone else to make me a Cars cake. Then I discovered the price- holy cow!!! Guess who is making a Cars cake this year?
I thought I would be smart and order a Cake decorating kit online:
Only to find that not much of it is actually included after all- most of it is cake and icing lol. Here we go again... He better think I am the best mommy ever after this!
So he will have the usual 3D cake (it is now the standard) and he is also having a Cars 2 themed birthday party in the park. Complete with a Cars Bouncy Castle. And Face Painting. And since he only wants Cars characters face painted and all of the face painters that I contacted don't do Cars characters- guess who is learning to facepaint? Lol I know I am a makeup artist but I have never been called upon to create the 'Finn McMissile' before.
I was just telling one of my work colleagues about MM's party (which is at the end of the month) and they did ask the question- "geez if that is what you are doing for 3 what are you doing for 4?". Oh crap. I have set the precedent. Where do I go from here? This guilt thing better get under control or it is going to cost us a fortune!!