Personal experience here... Estimates vs. Consultations. I can tell on the phone in two minutes and two questions whether they want an estimate (that should take 30 mins or less) or an hour & half (or 2) consultation. Right now I do estimates for free, because I'm assessing the tree/s, giving a price, and leaving (may do some explaining, but little.) I DO charge for consultations, however, because I'm not just assessing and writing a price. I'm looking over everything, they have questions about this & that, I'm explaining soil compaction and pore space as well as branch structure and crown raising, yada yada yada... They are benefitting from my time, years of experience, ISA Certified, Pesticide Certified, and such, and that stuff doesn't come free. I invest a lot of time and money into my knowledge base, and I charge to render that kind of expertise. If they don't like it, they can go get 'Joe Blow Bucket Hacks' to chop on their tree. If they want an artist who's passionate about the craft, then they're going to pay gallery auction prices...
To the question about losing good potential clients: If you conduct yourself professionally, KNOW what you're talking about, and can communicate effectively to them that you know what you're talking about, you have a big advantage immediately. Be honest and up front on the phone. If they are "good" clients, they'll listen and proceed, despite your costs. If they're cheapskates, the prices will send them running. Don't chase them. People call me because they're looking for someone knowledgeable about trees. 75% of my calls are referrals, even from University Extension offices. The ones that are looking for the cheapest bidder don't call me, and I'm ok with that.
Point is: "good" clients are willing to pay good money for good work.