Vodafone UK is now offering Lumia 520 in Black and White color models. PAYG price is £155 and it can also be booked for Free on monthly plans starting from £13. PAYG price is much higher as compared to what is being offered by O2 for the Red Lumia 520.  O2 is offering Lumia 520 for a PAYG price of £119.99.

Lumia 520 link