AITA for forcing his parents to spend thousands on a "custom" cake for his birthday?

I recently went to a birthday party for a friend and It's been bugging me.<br><br><br>I finally told my parents about it and they said "well, he's an ass and you did the right thing," but my dad also said it was an AH move.<br><br><br>So I'm coming here for judgment.<br><br><br>Our Glitter was turning 8.<br><br><br>Yes that's his real name. He was named that by his dad because he liked Glitter. It's a very uncommon name.<br><br><br>So, the kid and his family love anything with his name on it. His bedroom has the word glitter written out in glitter paint on letters. To the point we can't go to a restaurant without the parents asking for a birthday desert with his name on it. It's a big thing for them.<br><br><br>We get to the party. The dad comes up to us and says "remember, no store bought cake," and walks off.<br><br><br>We go into the kitchen and say, "wow, you guys have outdone yourselves," because we are people who say nice things, and they say, "yeah, we had a custom cake made," and we're like "wow, it's really cool."<br><br><br>Then they tell us they hired someone to make this elaborate cake and paid a ton of money because they're delicate and required special ordering.<br><br><br>We're like "wow," this is so cool.<br><br><br>Then we start eating and I comment that the flavor is really good, and the mom proudly tells us that the cake is actually Costco.<br><br><br>I'm like "huh?"<br><br><br>They're like "yeah, we paid thousands of dollars to this bakery but they told us they just ordered a Costco cake and decorated it," because clearly they lied.<br><br><br>We asked how they knew and they said they were actually going to return the cake and have the money back but the bakery is a friend of a friend so they paid for it.<br><br><br>I didn't like hearing this because it sounded like "wow, you spent a ton of money on something when you could have just ordered it yourself," but didn't say anything.<br><br><br>Then we go outside for cake and when the kid blows out the candles they proudly announce that they paid thousands of dollars for this custom cake and the kid is beaming with pride because he's one of those kids who LOVES spending his parents' money for no reason.<br><br><br>Smallest example was when he went to a restaurant and asked for 8 sodas, one of every flavor, just to prove he could do it.<br><br><br>So he's like "wow, thousands of dollars? That's so cool."<br><br><br>Then I pipe up, loudly, and say "you could have gotten this cake at Costco for way cheaper."<br><br><br>The parents kind of panic and try to usher me away but I'm like "you spent thousands of dollars on a cake that you could have just gotten yourself for way cheaper."<br><br><br>The kid is stunned.<br><br><br>He's just staring and looking super disappointed.<br><br><br>Which is what I intended.<br><br><br>They usher us away but it was kind of awkward for the rest of the party.<br><br><br>The dad called me the next day and told me that I ruined the party and said I should have just been quiet and let the kid enjoy.<br><br><br>I told him it was a stupid thing to lie about and spend so much money on and he asked if I was going to tell him that thousands of dollars spent on a carnival themed park party wasn't worth it.<br><br><br>I said that wasn't the point and he hung up.<br><br><br>AITA?