Cotton lined down jacket – any good for backpacking?

Be deliberate in keeping the piece dry, don't wear it while hiking, all the same measures you would take for a non cotton lined down piece. Nothing wrong with a little cotton IMO as long as you manage moisture.

$5? I say heck yea, grab it and use it. Backpacking is a simple and non technical activity, fancy technical fabrics are not necessary requirements of the hobby. This being BPL, yes, could of course find a lighter down piece for $150-350 more, but you may not find the benefits to be worth the expense.

$5..heck, even if you don't take it backpacking, for that price it is good to have in the car (just in case) or even for car camping.

As Eugene said, treat like any down jacket and you'll be fine.

As a a side note. some old school winter backpackers/skiers/campers still swear by Ventile Cotton.
http://wintertrekking.com/clothing/outerlayers/

Wonder if the material in the jacket is that type? (Based on the description?)

In cold, dry conditions the cotton canvas maerial breathes well, repels wind and 'fluffy' snow and is fire resistant.

Thanks for the link, very interesting stuff. The material seems very similar to those high thread-count sheets which sell for ridiculous amounts of money, and from what it sounds like that's basically what ventile is. I'll see if I can have a friend sew a shock cord in the waist since that's really the only thing this thing is missing. Awesome!

I almost felt bad for talking them down from $8 to 5, so I also gave them the asking price on a fully taped patagonia shell (it looks like goretex or H2No), which was $8.

A little cotton isn't going to kill you, and a down jacket is going to be fubar if it gets wet anyways.

Paul, ventile is a type of cotton that is woven so ridiculously tight that it sometimes looks like synthetic rain jacket material.

Dennis, the cotton could kill you or cause you a major case of hypothermia. You shouldn't even try it on.
DO NOT hesitate in immediately packaging it up so you won't be tempted to ever use it.
I'll send you $10 plus shipping, so you can ship it to me and I'll dispose of it correctly.