Hi does anyone know who offers the best rate for selling bitcoins for Western Union and how much WU costs 
I don't know the best rate, but don't expect a great rate I'm afraid. From the Selling Bitcoins wiki article, your options include:
Bitcoins in Berlin:
- http://bitcoinsinberlin.com
also ECurrencyZone and WM-Center
- http://en.bitcoin.it/wiki/Selling_bitcoins
Tenakha also lists Western Union:
- https://bitcointalksearch.org/topic/buying-selling-btc-for-gbp-pounds-london-oxford-108712
There have been others that have offered it but most have either quit offering it or shut down entirely.
