Hellow *client_name, we would love to be involved with this and provide you with some concepts to look at. Before we get started, however, I would like to clarify something:

You're providing us with multiple logos. How many different design concepts (not variants) are you looking for? We generally have a package we work with and we'd be happy to put a quote/proposal together for you to outline the scope of the job (amount of concepts, amount of variants per concept, amount of revision rounds, cost. etc), otherwise we can adjust according to your preferences.

--

even if you don't have an actual 'package' you've done in the past, just put one together. for example, if he has 2 logos, you could offer something like 2 concepts (original design concepts) each with 2 variants (1 for each provided logo) and 2 rounds of revisions (equals initial design, plus 2 rounds, so 3 total). moving forward, you can offer a fixed rate if you're comfortable with your estimating ability, or because of the amount of deliverables you're more comfortable with an hourly cost strategy, and your rate is $*/hour.

you won't just be blindly accepting, and it lays the ground for the projects so he can't come back and get you to edit 800 times. if you get through both revision rounds, and he's still unhappy, tell him you have a revision extension, and just apply the same pricing strategy.

you want to bill them as separate jobs. don't tell him about the revision scenario up front, but make it clear what your providing and for what cost. my friend just got dragged through the mud because there was ambiguity in the correspondence between him and his client: they wanted 3 concepts with 3 variants for the different ways the name could be displayed. he read 3 concepts, so he provided a price based on working on 3 concepts - 3 working files through the rounds and providing 1 final in the end, where as they expected 9 files to be worked on throughout the rounds and 3 provided in the end - 1 concept with the 3 variants finalized - for the same cost.

they're coming to you to provide them with designs. it's not up to you whether they actually use them or not, so you need to be paid to for doing the work. you buy a movie ticket, you don't get a refund just because it's a bad movie, the cinema didn't make it. you'd only get it back if they were at fault for you not being able to see it in its entirety - projector broke, someone caused a scene and security got involved, etc.