Who initially pays for the equipment that you want to raffle, and if it's not out of Hitech's pocket, what is in it for the donors? Will it be philanthropic players pooling new joysticks and mid level graphics cards, or sponsors with their own agendas that are never a free lunch. What will be the legal downsides for HTC if they host this versus it being nonaffiliated advertised on the internet? You can never forget the taxman is watching.
My wife's private university does something like this once a year with the proceeds going to a student grant fund. It's a dinner where alumni, business leaders, associated foundations, media figures, and political figures come for a 4 star dinner then bid on items provided by the university. The university foots the bill for the bid items or they are donated by sources, invitations, a year of meetings to bring in new interested parties, and the dinner. Everyone involved is getting something for their showing up aside from donating money by bidding. Personal exposure, advertising, and networking along with the good will from the community political and media figures need.
Still, a video game is not a university where the interested parties look at a dinner and raffle as worth the donation of money and time for the return in good will and exposure. Granted some of our players are not suffering for disposable income but, what will they get for this if they haven't already located each other and decided they need to give back to this video game to help advertise AH3?
You can start a crowd funding page which has a potential to introduce people to the fact AH even exists. But, once you have those funds, legally can HTC allow you to run an advertising campaign independently of them? You might innocently goof in your messaging and promise the inference of something Hitech has not coded or has no interest in promising. And how will the taxman look at your use of those funds?