Sure, the last time you browsed here was the sixth grade—but if you ignore the prom and graphic tee sections, there's actually a lot of stuff that adults can wear, too. I suggest browsing the well-priced denim (this pair of black jeans would look very grown-up with a button-down) and jackets (here's an under $50 chiffon blazer—seriously!) instead.
The trick to shopping here is to skip right over the knitwear and shoes (imitation wool, cashmere and leather often looks cheap) and go right to the dresses. Anything made from a chiffon fabric (like this $19.80 red one here) or lace looks pricier than it is, especially when you accessorize it with higher-end pieces that you already own.
There are a lot of members-only T-shirt websites, but this one is my favorite. Each costs between $15 and $25, but feels like a fancy $75 James Perse tee.
Much like Pixie Market, ASOS balances out expensive products on its website with a bunch of similar, less-than-$50 options. Plus, since it has sales so frequently, most of the pricey stuff gets knocked into the bargain range, too. (But while you're waiting for that $100 sweater to go half off, check out this maroon and grey $34.49 pullover and this elbow patch cardigan for $37.94.)
For every costs-more-than-$1,000 designer accessory you're coveted, there's a much cheaper, "inspired-by" version here. And because it's handmade, it doesn't count as a knock-off!