Getting a commission when not at a comic convention can be tricky thing. It usually works out as either:
1) Pay up front and get commission by an agreed date
2) Artist agrees to do the commission and takes no payment until done
In my experience most artists opt for number 2 (unless it's a really expensive piece then they might ask for half up front) so they don't feel time pressured to get it done in a hurry especially if they have deadlines for published work.
The question becomes, when you don't pay up front, what is a reasonable amount of time to wait? I guess it depends if a date or timeline is ever agreed upon. Anyhow, how is this relevant?
Just over two years ago I contacted Dan McDaid (Planet of the Apes and current IDW Dredd artist) about the possibility of doing a poilce line up piece for my collection. He was well up for it and was leaning towards Street fighter characters before changing his mind and opting for Superman villains (I had given him a choice of about 5 different character themes). These were Lex Luthor, Bizarro, Mongul, Doomsday and Brainiac.
So, he gets started in April 2015 and says he's not got much work on so should have it done soon. A couple of months go by with no contact so I hit him up to check on the progress. He said he had started and it was going well. Then no contact for until Christmas time. I contacted him again, no reply. I waited a month then send another email. He replied saying he was snowed under but hadn't forgotten me. Fast forward to late last year and he says he just has one character to go. Fair enough. By February this year it was coming up on two years and although I hadn't paid anything yet I felt the progress was too slow (barring one other incident the longest I had ever waited for a commission was about 3 months). I asked him on twitter if it was nearly finished. No reply
Then yesterday out of the blue I got an email from Dan saying it was done and ready for posting. He asked if I'd like to take a look at it. I said yes of course. Firstly I must say he went a bit off-brief as it isn't really a line up piece. Secondly he didn't include all the agreed upon characters. Thirdly, holy mother lovin' tortilla chips, I don't care about points one and two as he went over and above the call of duty here. It was most definitely worth the two year wait and I have zero problem with the creative direction he took. Wow! Sometimes g̶o̶o̶d̶ nutsack busting things come to those who wait.
You need to click on it to see the full image.
Also, I need help with some of the characters. The woman on the left with the M on her chest and the android thing behind her.