You might check out the Polo Towers on the strip near the Hard Rock Hotel. They have two bedroom suites with a sofa bed in the living room and a dining room and kitchen. It’s a lot cheaper than a hotel suite. http://www.polotowers.com

The Signature at MGM Grand looks Great, it is a newer building at MGM full of suites. I looked it up and the total price for one room for 4 people for 2 nights (Friday and Saturday) is $548. That is only $137 each. So if you purchase 4 rooms holding 4 people each for Friday and Saturday it would be a total of $1644 (still $137 each person). If you were wanting to stay for three nights the total would be $2928 for four rooms with 4 people each Thursday through Sunday. That would break down to $244 each person. That is still way below your $400 a person budget. Hope this helps. MGM is at an excellent part of the strip, we always stay at Excalibur.

To get such a deal, you will have to walk 2 blocks from the strip to Marriott’s Grand Chateau. This is an apartment style hotel with all the amenities you will need. Separate living area, kitchen and room space for up to 5 people.
http://www.lasvegas-how-to.com.....ateau.html
Another option will be Las Vegas Marriott Suites separate living area with a sofa bed, wet bar, and a mini refrigerator. Also 2 blocks from the strip.
http://www.lasvegas-how-to.com.....uites.html

Hope this helps