Nice idea. One issue is that most users will think that you have responded to the incentive to inflate the prices and make yourself look better by comparison. Some ways you can make your estimates more credible include:

  - 1) give ranges of price estimates

  - 2) communicate the uncertainty around different parts of the estimate

  - 3) show what size team you are estimating will be working on your project

  - 3b) have a slider so that people can play around with the team size (and explore the team-size / price / time tradeoff)
 
  - 4) show an estimate of what kind of volume the finished mvp can handle

  - 5) show real-life estimates you've gotten on a set of projects. possibly include how much it would have cost to build this very website at both a large institutional design agency and a well-regarded boutique agency.