Machka 

A "tip" is a ... what would you call it ... rubbish heap? landfill site? It's the place where a city puts all their rubbish.

A "tip shop" is a shop where usable stuff has been salvaged from the tip one way or another, and is up for sale, usually at quite reasonable prices, and usually negotiable.

So you might find a section with parts of houses ... old doors, window frames, bricks, etc. Another section might have sporting goods like bicycles, skis, golf clubs, etc. Another section will have furniture like shelves, wardrobes, etc. Then there will be quite a large section of smaller goods ... books, ornaments, electronics, etc. etc.

See the link above ... that's one tip shop in our area.


And here's another one, not too far away:
http://www.morningtonparkwaste.com.au/reuse_shop.htm