When I buy knitting yarn, I usually have a project in mind already - like a specific pattern I want to use. That way, I know exactly how much yarn to buy and what colours to use. It also minimises the risk of building a huge stash of yarns that I don't necessarily know what to do with.
But I have discovered Deramores. They have a subsite for New Zealand, so all the prices are in NZ dollars. And the prices are so low compared to local retail prices that it's hard to believe they are in NZ dollars rather than pounds.
It's very very tempting to buy just about everything, especially the Rowan yarns which are prohibitively expensive here (like, $18 for a ball of Rowan Jeans for example). But I want to support my local yarn shops and New Zealand yarns etc, so I'll try to stick to yarns that I can't easily get locally - like cotton or silk types. And Rowan.
It's so very very tempting...