How can we find bid amount for a keyword? Is there any tool except google adwords traffic estimator? Thanks in advance
testing is good way... However you get fair idea with Google Traffic Estimator and Inventory.overture.com
Your bid is dependent on your Quality Score, and Google can't accurately estimate your Quality Score before your campaign starts, since it uses the clickthrough rate (amongst other things). If people don't click on your advert, the cost per click to appear in any given position will be higher than if people do click on your advert. Regarding whether you should start low or high, if you have sufficient budget, you should probably want to start on the top half of page 1, though probably not the top couple of positions. That way, you'll get sufficient traffic to assess how much a click is worth to you, and bid accordingly.