I have reserved an SUV with National for 7 days for our January 2003 trip for $160 (with taxes etc. just about $200). This was booked with the Disney Club discount (which was 20%) and with Emerald Choice.
I booked an SUV last March with Budget (online) and paid $199/week (I think the daily rate was $39.99). We ended up with a Ford Windstar (after waiting 45 minutes for the SUV, they offered a minivan and they gave us a free day for the wait).