I'm inclined to let this 'type' of customer check others before calling me back for a quote. I know my costs and as others have said here, build a conversation that can instill a base level of trust and confidence. Offer them to get their best quote then call you back when their ready and offer yours off-the-top. BUT, only after a visual and physical inspection of the condition of the car will you be held to the quote. Most are understanding of this, if they aren't, well; give them their keys and let them move on to the lowest price.
