Price drop is going to pay off for Nintendo in the end. I don't think anyone expected such an aggressive move by Nintendo, they really have some brilliant people working there.
The value between the DS and the 3DS price would probably be about the same because of inflation But yeah, the 3DS wasnt much cheaper than the DS anyway.
$250 in 2011 has the buying power of about $210 in 2004 by CPI. The 3DS launched at a cost of 34 hours and 30 minutes at Federal minimum wage, compared to the DS's 29 hours and 7 minutes. So yes, the DS was significantly cheaper.