I bought S1 a navy Zegna blazer along with cream wool slacks to wear for his HS graduation a few years ago. He probably wears it at least once a week with khakis, jeans, or dressier pants. It fits beautifully, looks elegant and understated (no bright gold buttons, subtle weave, single vent). I hesitated to spend that much, but price per wear, it’s been worth it.
He does have another hand me down blue blazer that used to belong to H that he wears to parties where there’s the possibility drinks may be sloshed. About ten years ago, H and I traveled to a wedding where H was in the wedding party and was required to wear a specific blue blazer and tan slacks that he bought for the occasion. As we were getting dressed, I realized that I left the blazer at home. We made a panic trip to the only menswear store in the little resort town, and he bought an Austin Reed blazer (which, luckily, fit him pretty well). That’s now S’s party blazer.