oven tray advice - mine don't last!

[Jemster]

Hi
I need a couple of oven trays but can't find anything that lasts more than a few weeks. They end up looking dirty even after washing with burnt bits on and a horrible greasy smell. Do I buy non stick or if not what do I use to stop everything sticking? In fact even when I buy non stick things still stick!! I'm wasting so much money on trays that end up having to be chucked out.

[tinygreendragon]

I bought 4 trays from sainsburys for 99p each about 10 years ago and still just like new. All of which are used every day to make cookies (I sell them and make them for gifts for friends). No special treatment either, just water and washing up liquid.