Most cost efficient clothing list

For most of my BPing clothing I've bought dirt cheap from thrift stores.
I've found base layers (pat cap 1s), shirts(running shirts), pants (nylon zipoffs, running shorts), socks are all from them. Target's C9 line has many items that function well for BPing use. My fave pants are polyester C9 pants.

I've gotten lucky finding shells at TS also. Including a Eddie Bauer Goretex parka for my wife and a Marmot Precip for my daughter.

Agreed.

Target has a few different selections of poly shirts, both long and short sleeve, that are decently made and go for $10-15. I've something similar from REI and after finding these–from Target–and trying one, I went back for a few more. Walmart and Target both also carry the thin ("thin-thinny," as MC would say!) poly socks for good prices. They also have light-weight poly golf shorts that could work – I was already well set for shorts and pants, so I really didn't pay much attention to those items.

For a first backpacking trip I would focus on not bringing very many clothing pieces but using what people already have. The only caveat I would say is to enforce the no-cotton rule. Most peopley have sythetic underwear and socks (dress socks) already as well as a fleece jacket or wind / rain shell lying around. For a first trip these items will work with a weight penalty of course. The big key on keeping clothing weight down is to only bring enough clothes that you can wear at one time.

Base layers: Walmart $10 – $12 each for top and bottom
Insulation layer: Use what you have. Any fleece jacket can be picked up at Walmart, Cabela's or target $30
Shell: Use what you have or buy dry-ducks or if they want a nice shell spend $100 or so on a Waterproof Breathable. $25 Dryducks, $100 WPB shell
Socks: use dress socks or get at Walmart for about $1 a pair
Boots: use any running shoe in decent shape
T-shirt: Any non-cotton t-shirt they own or buy from Walmart $10
Hiking pants: Any non-cotton pants they own or Cabela's had convertable pants on sale for $30 last week
Underwear: Any non-cotton you own or Walmart for about $3

Total cost assuiming that you only own Shoes and buy dry-ducks would be about $120 so even if you have to buy shoes or want a nicer shell you would still be in the $200 budget.

This sounds like a really fun challenge.

Head to the thrift store. There are PLENTY of fleeces, running shorts, synthetic shirts, hats, old running shoes, etc. to go around. Bonus points for awesome colors.

I have a 600-fill down jacket that weighs 18 oz and cost me $.50 at Salvation Army. Seriously.

Driduck/Frogg Toggs sounds like a good bet too since a rain jacket might be hard to find used.

$200 almost sounds like too much if you go all used.

There are so many perfectly good clothes in this world, don't go to Walmart. (Ok, maybe for undies – which are more like $8 for 100% synthetic.)

If you like wool, you can find some VERY cheap military surplus wool sweaters. Good stuff, however not ultralight, but not a big deal so long as you are wearing it the whole day but can be a pain if you have to stash it in your pack most of the day.

Where are you taking them?

So weather shouldn't be too crazy, but it is the mountains so ya never know.