i'm the best discount shopper i know, i've built a wardrobe of only high-end designer stuff on a student budget, so if you live or work in westchester ny, baltimore or DC, read on!
i spend the majority of my budget at roundabout, a designer resale shop in scarsdale and greenwich. it's about $100 for a skirt, $150 for a semiformal dress, $200- $600 for handbags, $300-$700 for leather jackets, $100 for shirts. pricey for a resale shop, but their stuff is truly great, lots of tom ford era ysl, giorgio armani and rick owens leather, chanel bags, viktor & rolf, alexander mcqueen, hermes, etc.
for local boutiques, great stuff in scarsdale, rye and greenwich has good 50% and 70% off sales on certain things like moncler winter coats and raw 7 cashmere, and plaza too in bronxville and rye always has a 40% and 50% off sale shoe shelf where i've found kate spade, lilly pulitzer, coach and miu miu shoes for $50-$100. both of these places also do sidewalk sales.
i check out the designer clearance section of filene's basement in white plains and wait until it goes to 40, 50 and 60% off. they actually go to 70 and 90% off during certain weekends, but by that time nothing is left. i've gotten amazing stuff there, valentino leather coats, narciso rodriguez and moschino, a dolce & gabanna suit, see by chloe and d&g denim, prada bags . . . also an excellent selection of high-end denim (yanuk, blue cult, habitual, seven, miss sixty,chip & pepper) at ~ $80.
the clearance rack at loehmann's back room in white plains is also worth a look. you really have to search, but when you find something in good condition and they're having a promotion, it's worth it. i've bought three 100% cashmere luciano barbera blazers there for ~ $150 each. their shoe department is a similar situation-- generally worthless but i have found delman flats @ $40 and dolce & gabbana and fendi pumps @$80.
for denim, the best place to go is the havana jeans outlet on s. fulton st. in white plains (off central ave). nothing is above $60, and i've found citizens of humanity, levi's premium, diesel, yanuk, even da-nang silk pants. from november to february they do super clearance and sell off this stuff @ $15-20 per pair.
lacrasia in grand central station is also nice for cheap belts and scarves and high-quality hair accessories.
when i was in college in maryland, the loehmanns in baltimore was the best for very reduced alberta ferretti. the filenes basement in baltimore was AMAZING for its designer clearance, with stuff directly from barneys, bergdorfs, louis boston, and holt renfrew. people there are more conservative, so anything slightly avant-garde and the furs and suedes all got really cheap. i found hard-to-find labels like balenciaga, lanvin and behnaz sarafpour as well as the more commonly discounted prada, genny and dolce & gabanna. i guess designers who show in ny don't like to liquidate in ny because it kind of ruins their image, so the chevy chase loehmanns gets straight off the runway peter som, calvin klein, ralph lauren, and oscar de la renta. they also have several better contemporary lines like marc by mj, kulson, cacharel and duarte jeans. their shoe selection is great certain times of year, i've found sonia rykiel, christian lacroix, valentino, costume national. the filenes basement in chevy chase sucked except for lingerie, where i found ~ $175 panties still with their barneys tags for $15.
the saks in san francisco always has the most stuff for 60% off sale, and the sales associates there are the nicest! if you establish a rapport with them they'll ship for free too. i also like bloomingdale's in white plains for sales on really high-end denim and lacoste stuff-- they still have a good selection of sizes at 40% off. plus my best friend from high school works in the YES department, so if i'm ever going to buy anything for full price, i want her to make commission on it!
WEBSITES: i've always liked the merchandise and prices on yoox but have had some problems with their customer service. i like ebay for stuff that's otherwise prohibitively expensive, like tiffany sterling silver barware or nancy gonzalez handbags, but i'm very leery of it for most popular fashion items. i also like activeendeavors.com when they have codes and i want a specific pair of jeans.
places that are just not worth it for bargains (from personal experience):
toney, toni & the gang and havana jeans sales
neiman marcus (except for last call sale)
ebay for anything well-known (so many fakes)
WOW.. I am just so deeply impressed by your bargain-hunting.. if this is what you manage on a student budget you are going to have a Too Die For wardrobe when you start working jenimmacto !! CONGRATS !!