I think EMY sounds better. I'll try to get something close for less than $200.00, though.
Picking your dates is important: there can be a 2:1 price difference by just changing the date by one day - use the AmScan site to find the prices over a series of dates, or just poke the Amtrak site, pick a date, check the price, pick a different date and check the price etc.
This is a list of SAC-OMA prices I'm looking at over the next month:
Fri 09/13/13 Details 6 California Zephyr $178.00 SO $1295.00 SO NA
Sat 09/14/13 Details 6 California Zephyr $178.00 SO SO SO
Sun 09/15/13 Details 6 California Zephyr $222.00 SO $1295.00 SO NA
Mon 09/16/13 Details 6 California Zephyr $178.00 SO SO SO NA
Tue 09/17/13 Details 6 California Zephyr $178.00 SO SO SO
Wed 09/18/13 Details 6 California Zephyr $178.00 SO SO SO
Thu 09/19/13 Details 6 California Zephyr $222.00 $735.00 SO SO NA
Fri 09/20/13 Details 6 California Zephyr $141.00 $735.00 SO $1597.00 NA
Sat 09/21/13 Details 6 California Zephyr $178.00 $735.00 $1295.00 $1597.00 NA
Sun 09/22/13 Details 6 California Zephyr $178.00 $735.00 $1295.00 SO NA
Mon 09/23/13 Details 6 California Zephyr $141.00 $626.00 SO SO NA
Tue 09/24/13 Details 6 California Zephyr $178.00 $735.00 SO SO NA
Tue 09/24/13 Details 6 California Zephyr $178.00 $735.00 SO SO NA
Wed 09/25/13 Details 6 California Zephyr $178.00 $735.00 SO SO NA
Thu 09/26/13 Details 6 California Zephyr $178.00 $735.00 $1295.00 SO NA
Fri 09/27/13 Details 6 California Zephyr $141.00 SO $1295.00 SO NA
Sat 09/28/13 Details 6 California Zephyr $277.00 $735.00 $1295.00 SO NA
Sun 09/29/13 Details 6 California Zephyr $178.00 $735.00 $1295.00 SO NA
Mon 09/30/13 Details 6 California Zephyr $178.00 $735.00 $1295.00 SO NA
Tue 10/01/13 Details 6 California Zephyr $141.00 $735.00 $1295.00 SO NA
Wed 10/02/13 Details 6 California Zephyr $141.00 $735.00 $1295.00 SO NA
Thu 10/03/13 Details 6 California Zephyr $141.00 $735.00 $1295.00 $1597.00 NA
As you can see - the prices vary quite a bit by date... if you're not hemmed in by dates, changing your travel dates by one or two days can save quite a bit.