Never buy any.

I'm in electronics for a living, last thing I need is to have it as a hobby as well!

Saying that, I was/am a closet fan of Heathkit (way before my time I hasten to add). Crap kits but they did actually work, but more importantly they looked good - and that's where every kit manufacturer since has fallen down on - today they might work well, but they look crap and noddy (there's another word for you to look up Adam). That's only because an old retired Director of the Company was a friend of my Dads and I got to know a lot of the politics and what went on behind the scenes in the early days. Fasinating stories remembered and recounted over long dinners...