Well, filtering out calls is part of the game, yes. But I'd say we will go out and meet with customers and give them a written bid 90% of the time. Maybe 10% get filtered out over the phone.
First, most of our new customers come from our website. And our minimum prices for weekly service are listed on our website. So that filters out a lot of the cheapskates before they even call.
For existing customers wanting additional work, we'll always go out and give them a quote, no questions asked.
For new customers wanting maintenance work other than weekly service (e.g. clean-ups, mulch installation, etc.) we don't screen those too hard. That kind of work is quick and easy to bid. And we can do a lot of those kind of bids in a day. So we always take those leads.
The other leads we get for landcape installs, hardscape, design, irrigation installs, etc. we do filter out a little. But I don't like to tell people we won't give them a bid. So I just get certain information and decide which one of the sales managers gets that lead. If they are in an area of town that we don't get a lot of work in, have a low home value (we check on Zillow), seem rude or impatient over the phone, or certain other factors that I won't discuss in a public forum, then I will send that lead to one of my other sales guys in our company - because I deem that lead to be a low-chance lead. That is, we're going to have a low percentage chance of landing that job and I only want to spend my time on the leads where we have a high %. Some people we screen out over the phone just by giving them a ballpark figure. If they want synthetic turf, for instance, we'll tell them it generally costs at least $15 per sq. ft., installed. So then we ask them to measure the area out, multiply it by $15 and if that sounds like it's in their budget call back. Most do not call back. Which is a good thing. Because I used to land less than 10% of the Synthetic Turf bids I gave. Now that we have them do this exercise, I land a much higher % of those bids because those that do call back have already considered how expensive it is and are okay with the price.
I think your problem is that you need to hire another sales person / project manager.