I use Gixen to snipe. Costs i think £5 to use for the year paid via PayPal. It drops two bids in for you from different servers in case one fails. Can have it strike at 6 or 3 seconds. I usually just put in what i am willing to pay , if i get it for less it's all good.
It takes out the frustration of sitting and physically waiting for the auction to end then fumbling around last minute to drop the bid in , that's too stressful for me.