I always ask, "how much should I plan to bring with me?" which makes me sound like I have way more money than I actually do, but I also feel like it doesn't make it sound like I'm concerned with the price.
As a tattooer I try to quote people on their tattoo before they ask to avoid them asking. Currently I over quote people and then when I'm done with the tattoo I charge what I feel is a fair price for the piece (usually less than the quote). I think that it's good to have people prepared to pay more than they actually end up paying, at the worst it makes it seem like you're a nice guy who's hooking them up. In the event that something is really big and/or detailed I'll stick closer to the hourly rate and I tell the client that there's no way to give a real quote on the piece besides "whatever you're comfortable spending that day".
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I got my full side done in under 14 hours by a very renowned artist somehow. I will absolutely agree that artists that charge more are usually much faster (or at the very least, really good).
Sorry for the double post.