have you considered renting dvc points from a member and staying at one of the disney timeshares-you might end up with a great deal for around the same as staying offsite. you can do a 1 bedroom and end up with a better set up. you'de have the master bedroom along with the living room that has the hide-a-bed sofa (so basicly 2 private rooms). you would save MORE money because you'de have the full kitchen (we save loads by making one grocery stop for breakfast, snacks and drinks alone) and you could pack less because you'de have the full size washer/dryer in the room.
you have the advantage of being able to pool hop to most of the best pools the park has to offer, there are special activities offered only to/at the dvc timeshares, and (and this is a biggie for us) depending on where you stay-you may find reason to relax and enjoy the room. example-our most recent dvc stay was at ssr, we had a one bedroom non-preferred view, well we preferred it-it looked over onto pleasure island such that we could sit on the deck each night and watch the "happy new year" fireworks! it was great after a long day of park hopping to jump in the rental car (we just prefer it over disney transportation) and do a quick drive back to "our home away from home", but knowing if we got a mad craving for something to eat from down town disney-it was just a few minutes away.
you might have him take a look on the disney website and see what the dvc rooms are like, then have him look at how much the rack rate is and compare it to the current going rate for renting points (and it can differ widely how many points are needed depending on if you want to go to a more popular destination over some of the tried and true).
the other thing to remind him of-is most of the orlando area timeshares that offer "great" rates for non members require a several hour time share presentation committment that usualy ends up schedualed in the middle of the day (and ruins that day for much time at the parks)-if you opt out of attending they hit your credit card for their full rack rate (so the room that ran $50 per night, may end up being $300 per night

).
i a big believer (even before becoming a dvc member) of staying on-site, in fact when we go in a year or 2 at least one full week will be devoted to universal and other destinations, but we will still stay on-site at wdw-we can't beat the quality and service.