Shesho Designs is a local underwear maker who sells her stuff around town and has stuff available on Etsy. I've never bought anything from her, but they look cute and comfy! She takes custom orders too.

http://www.etsy.com/shop/sheshodesigns

Zovo Lingerie in UVillage! XS-4XL, how's that for size? Everyday cotton to fancy schmancy lace, $5 to $100, whatever your heart (or serious ass) desires. Zovo is a local company and carries products made in the US, and around the rest of the globe.

My friend K.T. swears bt the undies she bought at Retail Therapy on Pike, right off Broadway. Pretty cute, pretty indie, pretty pretty..

The laundry room of my apartment complex. They also make a lovely hat.

I know of this great local design company called Harebrained that have a line called Period Panites. I've seen them at some of the local craft fairs but you can buy their stuff online at theperiodpanties.com
They have awesome shirts as well.

Best place to get good undies is from Idolatre on Etsy. She's local (so if you're in Seattle, you can pick them up at her events), makes great panties out of clever, cute fabric and they're comfortable and attractive on any sized bum. I wear 'em and recommend 'em! Here she is:

http://www.etsy.com/shop/idolatre?ga_search_query=idolatre&ga_search_type=seller_usernames

Les Amis in Fremont has lots of pretty, sexy (in a demure French sense) lingerie. I haven't been in a while so I can't answer your " will they fit a serious ass" question, but I do remember their selection being quite beautiful. They have a lot of lace, but it's the soft kind.

www.theperiodpanties.com

Local Seattle group, usually at I Heart Rummage, online orders available. High quality (American Apparel), hilarious product. I like Evil Beaver myself.

I like this question! I don't know of any local shops or designers that make inexpensive, cute, cotton undies, so I'll be watching for better answers than my own.

In the meantime, American Eagle (in various malls all over) fits your other requirements. I've never bought clothing there but they are always having sales on cotton panties. They are often priced 5-10 pair for $25, and they're mostly very cute. Some have bits of lace, some are patterned, some are plainer. If you're concerned about fit/coverage, they have a lot of options in the boybrief and boyshort styles.

Most of my other cute underwear was pretty expensive, unfortunately. So I'll second your question. Any local seamstress entrepeneurs willing to foray into panties?

I know some these items on the net. Just like this Ladies Cotton Underwear Size XL:
http://www.uxsight.com/product/19046/comfortable-fit-ladies-cotton-underwear-size-soft-pink.html
Hope this helps!

I hate to say this since it's not a local shop, but these from Old Navy have become a complete staple in my drawers drawer: http://oldnavy.gap.com/browse/product.do?cid=36878&vid=1&pid=682591&scid=682591362. They are cute, comfortable, will fit a serious ass, and come in a bajillion colors/patterns. You can avoid the mall because you can buy them online.

And then, as someone else suggested, assuage your guilt with a few other local biz shopping trips or restaurants...

I third Retail Therapy

I'm a diehard local shopper but I've had a hard time finding indie undies. I honestly think Forever 21, Target, and Old Navy have the best underwear--and they're cheap. You can always asuage your guilt by shopping locally for everything else.

I know they aren't local, but I'll agree with the Target suggestions. They have a section that has undies @ 5 for $20 and the boy shorts fit just perfect. Best undies I've ever bought.

I like the Gap's cotton undies, but, alas, not local.

I was going to recommend Pants of Fancy Schmancy Pants, but it appears that, while Fancy and Schmancy are still around, Pants is kaput. Anyone who knows different, feel free to chime in.

Target. No joke. My favorite, comfiest, cutest underpants are from Target.

No local advice for you, though. You could try lemon sugar in Greenwood, but they're not cheap.

Salvation Army!

Oh, I'm in for it now.

J.C.Pennys.... awsome sellection!

Any place that sells Hanes.

No, seriously.

Turns all us str8 bois on.