For those recommending Macy’s…your stores must be a LOT better organized than the ones around here. I would rather spend a little more money, and be able to actually find what I want. That’s why I go to Lord and Taylor.
But back to the question…your daughter should decide her budget. Some of the Rent the Runway dresses cost as much to rent as it would cost to actually buy a nice LBD which could be used again with different accessories.
https://www.renttherunway.com/shop/designers/slate__willow/amy_dress
https://www.renttherunway.com/shop/designers/nha_khanh/west_dress
https://www.renttherunway.com/shop/designers/carmen_marc_valvo/cranberry_jacquard_dress
I would avoid low cut or low back. Even though it is a cocktail party, but it is still a company party. She should still look professional. She shouldn’t look like she is going to a prom or a sorority formal.
I agree with not to low in front or back and not too short. We have no Lord & Taylor around here. Mostly, we just gave Macy’s. Banana Republic and Ann Taylor gave nice dresses as well. My D and niece both like their career clothing.
I’m more a fan of the Macy’s selection on the web than in their stores–can’t find sizes and small selection in our stores.
I really like the first dress @oldfort linked. But there it is…a little black dress. I will,say…the OP would not be buying a dress of that quality for $40. Its classic, however.
I think every woman young or old…should have a LBD in their closet…because you never know when you will need one.
Exactly @thumper1, RTR costs and fees add up to what a nice dress would cost at Lord and Taylor or Macys, with all the coupons and sales. Heck, even Nordstrom may be cheaper, with free shipping and free returns.
http://shop.nordstrom.com/s/tahari-notch-neck-crepe-sheath-dress/4436312?origin=category-personalizedsort&fashioncolor=NAVY
http://shop.nordstrom.com/s/lauren-ralph-lauren-jersey-sheath-dress/4404866?origin=category-personalizedsort&fashioncolor=CLARET
Another vote for Rent the Runway.
My D likes Banana Republic for work clothes also. Target online has cute party dresses also. (its where I got my MOB dress) You can try them on and return to the store.
I have to laugh at some of the comments, wonder how I ever got through 54 years not having a LBD. 
Our Macys is very nice and organized. The dress department has tons of dresses in stock…I know were are lucky.
Nordstrom is having their big fall sale. http://shop.nordstrom.com/
I think this gal needs to decide if she wants to own a dress (that she might or might not use again), or rent one.
Maybe she can go with a friend and try on some dresses…she might find something she really likes a lot. She can also look at Rent the Runway for options.
I’d vote for a simple black or navy dress, well made. Invest in tailoring. It will last her for years. IF it’s basic, nobody will notice when she wears it again and again. And again! She can wear different jewelry with it, a jacket, shawl, etc.
At the risk of sounding like my grandmother, a tasteful cocktail dress should be in every girl’s closet and a string of pearls in her jewelry box.
This one looks understated, classic and refined… http://www1.macys.com/shop/product/calvin-klein-illusion-banded-dress?ID=2980899&CategoryID=5449#fn=SPECIAL_OCCASIONS%3DParty/Cocktail%26sp%3D1%26spc%3D885%26ruleId%3D19|BS|BA%26slotId%3D23%26rdppSegmentId%3DCTRL%3AST
Is there a Nordstrom Rack near by? I order 10-12 dresses online for my girls so they can try them on at home (free shipping) and then return the ones they don’t want. Many cocktail dresses are in the $50 - $70 range.
Am I the only one here who shops resale and vintage shops?
I’m wearing a gorgeous dark chocolate color velvet dress to DHs holiday party. It cost me $10 at a resale shop.
Resale shops can be hit or miss, charity shops even more so. It’s a good option if the young woman has time to shop, because she’d probably have to visit more than one. And whoever complained about chaos at Macy’s… Goodwill will be a lot worse.
Upscale consignment places can be pricey. I bought a vintage Carolina Herrera work dress on 5th Avenue for over $100. Worth every penny and all, but I have the money and can afford impulse purchases.
Thanks for all the suggestions. I think we will hit Lord and Taylor and Macy’s (have been lucky in those places in the past) and if we strike out at both of those, then Nordstrom Rack (haven’t really shopped there before). She hates to shop, so we will do a mother-daughter shopping excursion when she is home next.
“Am I the only one here who shops resale and vintage shops?”
Nope, not the only one! I shop RealReal a lot. Actually, not a bad place to look for party dresses.
Here it is. I took the pin off.
https://www.tradesy.com/dresses/talbots-velvet-evening-holidays-dress-brown-7892467/
@Kajon, I think the dress you linked in post 31 is lively but maybe some younger women would think it looks too old. I agree no lie necklines or backs or ultra-short dresses.