To your question "If no one goes, does the MWC still get 380?" The answer is the MWC will always get some money from the BCS every year. That money is guaranteed to all non-BCS league teams and as noted this even includes all FCS leagues (formerly DIAA) The amount of that payout is not always 380K - see more detail on that below.

I did not take the time or see the value of detailing absolutely every option. I did the High and Low. And honestly based on some other info people posted it is clear that the Low might occasionally be even lower. The 3.8 million was likely because the MWC had 3 teams in the top 25. If that doesn't happen in a year then the 3.8 may even be lowered to something more along the lines of CUSA or MAC numbers (particularly if those leagues replaced our top 25 teams).

Either way the High IS the high. The Low is a decent indicator but not the absolute low.

That said another poster (cgrs) provided a doc link to the BCS payouts and as I showed in my response to him the average over the last 5 years (2005-09) the MWC received from the BCS was 5.6 million so that comes to an average payout of $560K to BYU per year. That falls closer to the low side of 380K vs the 980K of the high years.