Funnily enough the best pair of dancing shoes I had were a pair of Dunlop trainers I bought onlone for £3.99! I found them using Money Saving Expert's Amazon Discount Finder! An absolute godsend of a thing! To this day I haven't found anything more comfortable to dance in, they weren't too grippy either.
Second to that a £50 pair of basic work shoes I bought from Next and nearly threw out 5 years ago.
The worst have got to be Converse, anything where the ankle carries too far up just twists it and makes it very hard to turn!
I've yet to buy a proper pair of dance shoes, so suggestions also welcome from me! :)