If they say they've got $500 to spend but they want the final deliverable to include "$2,000" worth of detail and design quality (owning the work when it's finished besides), the situation is not going to end well 99% of the time. With certain types of map design styles, people who do not do map illustration/design for a living simply do not appreciate all of the time and effort that goes into producing quality work.
Anyone at CartoTalk could make you a $100 map! That might only buy you 90 minutes to 8-10 hours of design work though. For what it's worth.
Very well put Derek. I would add also the flip side of map buyers who want a complete map of the World for $100.00 -‘just make it fun and simple!’ : Map designers will often agree to do a cheap map with good intentions but then find themselves compelled by some inner need to put far more work into it to maintain a certain standard. I have fallen (and still fall) into that self-made trap too many times and it is bad for the whole industry