Very nice tools, especially considering they are an "early" effort. Might I suggest that if your friend insists on compensating you, an interesting lock or two is probably more worthwhile and equitable than money. I make a lot of tools, and even the simple ones often take multiple hours.
What's your time worth? Even at minimum wage, you'd be looking at 15-20 bucks a pick if you were being paid as though this was "just a job", and a skilled craftsman would command a much higher price. Fortunately, we do this for fun, not profit, because few people would be able to afford handmade picks. For fun and inspiration, look at some of the picks Raytoke
produces. I don't think anyone will disagree that his work is orders of magnitude beyond most picks, including pricey factory made "real" tools. I can't/won't comment on his prices specifically, but I know how much a few of his picks went for, and they were shockingly affordable. The only reason mortals can afford picks like these is because the makers are doing it for fun and basically giving them away.
What I'm getting at is that any sort of "payment" is really more of a token of gratitude, and at best should be thought of as something to defray the overhead cost of your hobby or keep you interested (in the case of things like trading for locks).
Bottom line: have fun. If your friend feels the need to say "thank you" see if he'll express it with a donation of his own time. (Like hunting down and purchasing an interesting lock)