You're a bit lazy - it's not as if spare parts for domestic appliances are difficult to get hold of.
Try searching using something like Google or Yahoo for online spares suppliers - e-spares are a well-known supplier - I buy my bags from dustbag.co.uk... they include filters with the order.
As for cost - your chosen supplier will tell you - postage will be extra.
You might also be able to create your own filter from suitable material lying around at home - or wash out the one you have.
Good Luck...
February 2017
Automatic Answer
While you wait for answers, we may have found some information which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix vacuum cleaners.