There's the story about the old guy that was selling woodworking stuff that he'd made... a customer came up to a chair he had and asked "how much"
"$100" the old man said
"Great!" said the customer, "I'll take 8 of them-- can you make them for me?"
"Sure" says the old man, "that'll be $1500"
"$1500!?" says the customer-- "but you only want $100 for that one!"
"Yes" says the old man, "but the first one was fun to make... the other 7 will be work"
I guess my point is this-- if this is a favor for a friend and you will enjoy or learn from it, eeking over whether to charge $50 or $75 is not in my book worth the mental effort... if it'll be fun, come up with a price that you both will be happy with-- in my mind this means covering my expenses and getting enough dough to cover a new router bit for every couple of hours "fun" it will take... If however, this will be work... come up with a price that you would be happy with if you had to make a dozen of the item... after all, you should be justly rewarded for WORK and ARTISTRY that you do-- If there is a deadline and it will add stress, this almost always pushes a project over to the "work" catagory for me.
None of this is to say that you shouldn't get paid for your craft... far from it... I can only guess the actual labor hours you have in that piece and I'll just guess and say 4(ish) actual hours of work (at least with the dovetails being hand cut... so probably more really and at 4 hours you'd be working pretty quickly) and around $20-25 in materials (and shop stuff like sandpaper, finishing materials, scroll saw blades, etc etc?) If these were the numbers I was looking at I would probably charge a friend a "fun" price of around $75 just to cover expenses and maybe buy a new plane iron or router bit...
but to make a one off custom made item that I considered "work" would have to be more... probably double the friendly rate which would work out to around $25 per hour which is a little more like what many artisans makes for their work
....as for a custom made piece that is your "signature work" I would also not skimp on the detail work... this is afterall your signature work... but that is just me...
Beautiful tray once again... sorry if my post rambled on a bit (I do that)
Lawrence
ps- oh yeah... and according to my old buddy that taught me bowlturning the price also drops relative to the attractiveness of the customer... unless you are a mechanic of course