Yes, but we don't have control over the prices unfortunately. Think of it like eating out at a restaurant. The food can be great (or horrible sometimes) and costs you a bit more than eating at home. Just like with food, there's many resources to help you DIY an e-juice you'll like at a fraction of the cost.
While I haven't found any vendors that change their prices according to nicotine strength, there's plenty with a lower price tag than the common $20 for 30ml. I just recently started DIYing, couple of days ago, and found it quite easy and enjoyable and having used a recipe for a clone of a juice I like, I'm really enjoying my juice. Great way to lower your costs.