I think the argument is more about how cheaply these commissions are being offered at the expense of the general collecting community. $5000 only covers the cost of about 5 or 6 full figures. That's a steal really when you may possibly have had 30 people who would have instantly bought this figure. It's possible Rainman doesn't really understand the value of the subject matter or his core group of support.
This type of work isn't a canvas painting, it's more like pottery or ceramics and usually those types of work, as a commission, are offered in editions of atleast 5 if it's meant to be very rare work like a Jeff Koons or Takashi Murakami sculpture (Just an example, 1/6 is no where near the same league as Jeff Koons or Murakami
)
An edition of 5 at 5k a piece would have covered the bar and would have given a pool of different types of collectors a chance at this.
As a collector, the commission of Popular characters isn't justified if the main base of support for your business is left out from being offered great works. An auction of this would have been much more commendable, but Rainman is free to do as he pleases and he has.
I guess the only way we'll see how this turns out is based on the level of support he'll receive if he continues to do popular Instant Sell characters as 1 of 1 commissions.