As I'm writing this I'm wearing a pristine ivory cashmere cardi I got in a consignment store. Can't remember if it had been new with tags, but you should never say absolutely never....I think the overall bar the store sets should be a consideration. Of course things will cost more in those cases, almost always, but still cheaper than a new item (at least one would hope).

I collect ski sweaters from Norway/Scandinavia and so I always look through the knit section specifically for those. Touch tells you right away if it's wool (although unlikely that the pattern wouldn't be a dead giveaway). I have bought a couple that needed buttons as the replacement was worth it.
Most of the thrifted sweaters I donate to use for raffle prizes for a heritage group I belong too but I have one or two I have saved out for myself. Have not yet explored ways to make these FAB yet but I try to make them look modern and fun.

Brilliant tips, Shannon. Our charity shops in the UK, as Mander says, tend to have a lot of basic high street stuff, although still worth a look if it's a trend you want to try without paying the full price - I regularly donate to my favourite charity shop, and as I am working my way through purging and buying (and sometimes making mistakes) I know there is some good quality stuff there, too. I've found higher end things in amongst the cheaper stuff, it just takes commitment to keep on looking ...

Mander, we do have consignment stores in the UK - they tend to be called 'nearly new' shops though, or dress agencies. That's what I did with all my formal office suits after I'd left work after having my first son - I sold them at a dress agency!