Take a big tool box with you mate and just pop 'em inside on your way out....... erm no i mean....
I wouldn't give more than £20... for the set.... Best thing to do is Haggle over the price.....
After all... Scap dealers only pay around £15-£25 per Tonne for a scrap car...
Best Advice.... Be Cheeky..... If you have to remove them yourself and they give an over inflated price, say "Ok, i don't think i'll bother.... I'll put 'em back on the car" and start walking away.....
They're desperate for cash so they'll come down on price....