I've gotten a few through Stitch Fix. If you don't like it you can not buy it and send it back.

Ok I looked, Massimo is $200-$400, but worth it.

I bought a beautiful blazer from Zara (online) and Massimo Dutti recently. In the $100 - $200 range.

I love Argent—have this and 2 pairs of pants for a standard suit.

https://argentwork.com/collections/blazers/products/single-button-blazer-in-seasonless-wool-navy

Stay away from the knit blazers at JCREW. Amazon makes them too but they really are bulky, shapeless and not flattering.

I started with a $150 budget but after a year of looking, I'm willing to pay $350 or so to get a good one.