I hope you bear with me. This is going to be quite a long post. I want to lay out my situation in detail in hopes of getting advice as to what I should do and how to approach it the best way possible.
I met this client 3 years ago when I was still a student. He hired me as an 'on-call' graphic designer, meaning I would work for them if projects arise. Most of the time I do packaging design—from the label to the box itself. I also handle the final artwork with every material that goes to the printer (which I just learned and am still learning as we go along).
I don't work at their office. I work from home. We talk online. We meet if necessary. I go to their office if I have time (since I have day job). And if I do, I work DIRECTLY and BESIDE him as HE GIVES comments right away.
There was no contract or whatsoever but we verbally agreed I would be paid for every 2-3 projects—which weren't difficult but they require the right creative direction to nail the what he wants—at about $400.
However, from March to July, I worked on a couple of new projects and old projects for revisions. I was waiting for him to pay me after our last project in July but it was almost September and I still haven't gotten it. I sent him a message telling him about it and even sent him an invoice detailing the projects we did.
He was surprised I was charging him $600 for that time period.
We then met up to settle this time and here's what we agreed on so far. I would give him an amount that I think is reasonable for the work and projects rendered during those months. And now moving forward, we would agree on X money every month if there's a project and X money if there's none. I would send him both figure and see if we could agree on it.
I told him $500 for the work rendered in March - July. I said $250/month if we have a project, $80 if there's none.
He didn't say anything about the $500. But he thinks $250 is too high. He told me that I should have a basis for this but I don't know how else I'm going to justify the rate. I based it on the number of hours it takes me to work on a single project — including but not limited to brainstorming, researching, designing, setting up the files correctly, etc.
I then replied him with a range instead. I said that the projects we do usually cost $150-300. And whatever amount we agreed on, I would be charging him $10 per hour on top of the monthly. He will not be charged on months when there's no project.
He said his issue he cannot verify the number of hours I put it. And he wants me to think of another 'formula'.
I think what I proposed is the best since he will not have to cover any additional cost when there's no project. I think the problem now is that he does not trust me with the number of hours I'm going to charge him for.
What can I do to make sure he trust me with it? Or should I find another 'formula' to charge him for?
Any advice is greatly appreciated.
P.S. Yes the rates are low but they're more or less near the "market rate" for the kind of work I'm doing.