[xn]

I use ranged estimates with LiquidPlanner. I send a project plan showing the estimates and expected completion date. If the estimates are wide, I explain that I can make them narrower by spending more (billable) time doing research.

Here's an example for a small project with a new potential client I met with for about 20 minutes: https://gist.github.com/bc2f83544b210f81715c4f4175fca985

Estimates are fairly wide because I haven't seen any of their code, just a brief screenshare and a description of the work they would like completed.