Stealth/Quiet budget fans

its all in the title what is a quiet cheap fan my budget is about £30 only need it for a 60x60x120 tent have one fan already which will blow air in this one will be used to pull air through the carbon filter or push it w/e

Don't really think that amount of money is gonna get you what you want. I've got a tent about the same size w/a Hydro-Farm 6 inch fan for exhaust and
I paid $100 for it. Sounds like a fucking jet engine too. These are supposed to be about the quietest, but are rather expensive. Good luck.
http://www.sunleaves.com/detail.asp?sku=SW604

what about if i use insulated ducting?

i have just bought one of these as im skint.http://cgi.ebay.co.uk/hydroponics-grow-tent-inline-extractor-fan-TT100mm-4"_W0QQitemZ250589287998QQcmdZViewItem?rvr_id=140209344047&rvr_id=140209344047&cguid=79aac0021290a0aad4e60616ff50daf1
im only growing in a wardrobe and not sure if its big enough for that but it was cheap so well see how it goes.

yeh keep us updated dude