If you don’t want to splurge, you'll appreciate this MM6 MAISON MARGIELA Blouse. It's a great choice and a great investment. Another good option is this IRO Blouse. It's an item you'll fall in love with which also doesn't cost a fortune. You might also want to consider this Tome Blouse. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
If you're looking for something in between pricewise, opt for this Issey Miyake Blouse. While the price is very reasonable, this piece is an easy wardrobe update. You might also be interested in this Blugirl Blouse. It's an attractive option both price and quality-wise. Alternatively, opting for this Helmut Lang Blouse is a great choice as well!