I bought mine through Grimco, I paid just under $17K. That was with a Epson $3K rebate and a $1k SGIA show rebate.
Haven't dealt with Big Systems, but would highly recommend Grimco out of Chicago.
I've had the printer up and running since Nov 3rd, so far very pleased. No issues at all getting ink. I bought one set with the machine and another set for stock maybe 2 weeks ago. Got everything next day.
Good luck, Don