Lock all your garden gates as well. Lock your back door (of course) and hide the keys in a place the low life won't find too easily.

I have learnt this from bitter experience - if you make the escape routes hard you are less at risk and less will be stolen if they do break in.

Re tools - I always buy cheapish, because I'm always thinking i'll mislay them and leave them out in the rain for months. Even some fairly cheap ones have lasted me a decent length of time, though. The very cheapest usually disintegrate after a few weeks.

I agree with the comments on the better quality of vintage tools - same with clothes, furniture etc. The old ones are the best, innit.