The cost of your colored contact lenses will depend on a number of factors including the brand of contact lenses, the type of lenses, and how many pairs you want to buy.
You can typically expect to pay about $30-$40 for a box of colored lenses. However, if you buy in bulk, you can often expect to get a discounted per box rate.
For instance, if you buy 4 boxes or more you can often get a discounted rate on your lenses at sites like AClens.com
To ensure the safety of your eyes, always remember to first obtain a prescription for your colored contact lenses from a licensed eye care professional.