I've done some artwork for somebody, not a friend, but a friend of my brother's fiancee, who approached me to do the work. It's for her husband-to-be, her present to him at their wedding this weekend. She wanted me to create a two-page spread of a comic book that told a few anecdotes from their relationship, and also to have a cameo by Judge Dredd because he's a massive fan.
I met with her for about an hour and a half to find out what stories to use, then wrote a script based on that, designed the layouts, pencilled, inked, coloured, scanned, edited and printed the work. Then bought a comic, stapled it in to that so it looks like it's part of it, and mounted and framed it.
All in all that was probably 40 hours of work. Now comes the awkward part of setting a price. TBH I didn't set one in advance because I just had no idea what work it would entail, and it turns out it was a lot. She agreed that we'd set a price after, and has told me to charge what I think it's worth, she's not asking for mates' rates or anything, since she was the one who commissioned it. Thing is, I've never done anything on this scale and have absolutely no frame of reference. Does anyone want to randomly say a number they think I could charge? I'm not a professional illustrator or anything so I'm not going to charge crazy money, but I feel like I need it to have been worth my time. I did all this in under 3 weeks while working my normal job, so it was pretty full-on.