Great question Neha. 'Bidding strategy' is one of the key areas to produce success in Search Engine Marketing. One obvious variable which influence bid price is competition. However, there are number of other important factors such as:
Your Objectives: If you are looking at driving higher traffic in a shorter period through SEM then you should be willing to bid higher to increase your ads impression %.
Your Margins: If you've a higher margin for the product/service you are promoting through SEM then you would be willing to bid higher than your competition
Even if you can afford higher bid, you should always look for optimising your campaigns to reduce your bid price and one of the best ways to achieve that is by improving Quality Score of your keywords and ads. Higher Quality Score leads to lower CPC (Cost Per Click). The following table will help you understand the value of Quality Score.
Hope this helps?