But it isn't just about the bargain it is also about not creating demand. I hate that every new purchase I make tells the manufacturer that their item is needed, the knock on effect is pollution, often slave labour and environmental wastage. I like that I can buy an item that is used and know that I am not contributing to that waste :)
Obviously, we usually come home with items that weren't necessarily needed but usually I try to go when I need stuff so it isn't a purely wasteful spend.
Things I will always go to op shops for first before buying new is:
Clothes - kids grow so fast it really is a waste buying new all the time. I also find most of my clothes at op shops, I am about 2trillion steps away from being the coolest kid on the blog LOL
Household needs - spice rack, washing basket, clothes airer, curtains I usually manage to find what I want.
Furniture - I got the coolest retro 50's dining table and chairs for $60 plus heaps of other bargains over the years, including antique drinks trolley, bookshelves, desks, cupboards.
Books - oh the books, heaven! Fabulous for homeschoolers too. Parents buy those dinky little workbooks and said child says "NO WAY!" so book goes to opshop unused. Great for texts too, especially if the uni is near the opshop. I picked up some bargains at Prahran when I was at Swinburne there.
Games & puzzles - again, you can pick up some beauties. I love the Ravensburg puzzles and have got a few this way. Make sure they either say on them that they are complete or ask to look thru to make sure they are. If little markers are missing you can always borrow from another game you have, same for dice.
Things I won't buy at an op shop:
Electrical goods - unless I am 100% sure they work I won't buy.
Shoes - I am careful with this one, if they are new or not worn down in any way I will buy them
Underwear - for obvious reasons of course
Mattresses - this just pushes the op shop friendship a tad too far for my liking
Grocery items - nowadays many of the bigger stores will have grocery items that are usually junk food anyway. I won't buy because they are more expensive than the supermarket usually.
A great list of op shops in Tasmania can be found at opshops.org and you can actually search Australia wide by post code on the same site.
Another great way to find a bargain is with Freecycle. This is a yahoo list based group that gives you the opportunity to give away unwanted items or to find things you are after. It is world wide and you can go to the main website to search for you nearest group.
And most importantly don't forget to give back!!