We went in AUgust, 2 adults and 4 "children" (23,21,19,14) and stayed in a 3 bedroom condo at Holiday Villas, like 5 min from WDW. I checked prices, then bid on it at skyauction.com got it for $80 a night. We drove to FL, so we had cars, and it took less than 10 minutes to be parked at wherever in WDW from the condo door. I know some are die-hard "on-siters" but, this was good for us, even on days we left and went back to condo in afternoon it wasn't a hassle.
Our whole trip was $3000, or 500 pp. Driving down there really helped keep costs down, but airfare would've been say 250, so we still could do it for 750 ea or right at 5k for 6 people for 6 nights, including food (2 character meals: PSB and CM, Mama Melrose Fantasmic pkg, and lunch in park everyday, dinner in parks all but 2 days when we BBQ'd at villas), passes, water park day, and $50 souvenier money pp.
We had an awesome trip, and for us, staying off site was best for that combo. Dh and I are going back in DEc for our first on-site stay, so maybe I'll be "converted" then.
Things your friends might try:
1. rent dvc points or do a suite/deluxe room (WL has deluxe rooms, don't know how many they sleep)
2. stay offsite in a condo w a kitchen (breakfast for 6 at wdw is easily 40 for contiental to 100ish for character meal)
3. don't go to big parks everyday, maybe do 2 days on, one off, or big park, water park, big park, pool/dq, etc
I'm a newbie, but a budgeter at heart, so hope they can go and have a wonderful trip!