Really, assuming a 30% discount off list price, the 2004 and 2012 have a price delta of around 200 dollars.
Hmm...I think your calculation is a bit off.
KD0RC got the Agilent DSOX2022A, which given the current promotion is priced as the DSOX2012A ($1572). The DSOX2004A is the bottom rung 4ch version --- there's no promotion on it --- priced at $1916. That's $344 more, for 2 additional channels at the expense of a lower 70MHz BW.
As Dave pointed out, four 70MHz channels (Rigol DS1074Z) could be got just $206 more (using 6% discount on Tequipment) than getting the DSOX2004A, and he'd have totally 2x 200MHz channels and 4x 70MHz channels!
KD0RC, I think you made the right choice --- the bandwidth upgrade is a very good value; I also took advantage of it and ordered an Agilent recently.