@cfiesler I've thought for a little while that organisations like ACM and IEEE should have a permanent staff of professional conference organisers.
Academic conference costs are completely out of control and part of this is because much of the negotiation power is held by the venues. The accounts I saw for one ACM conference had $50/person for lunch. The lunch was an incredibly mediocre buffet and you could eat much better for half the price in dozens of restaurants within a 10-minute walk of the venue. The first conferences I went to didn't cater lunch, they just gave people a couple of hours to go and find somewhere to eat, which led to a load of interesting conversations as you found a group to eat with and went somewhere nice.
The cost of renting the AV equipment is often higher than the cost of buying it outright.
Is it cheaper to not cater and not have the venue provide AV? No, because if you don't use their catering they charge you more. If you use your own AV equipment then it must be operated by members of the union (which is often an organisation local to a single hotel and controlled by the hotel management) and the union rates are so high that it isn't worth it.
If you're a single conference, negotiating a better deal is hard. But if you're the ACM, organising over a thousand conferences every year, you're in a really good position to negotiate with a hotel chain. If ACM goes to Marriott or Hilton and says 'we want a good deal for our conferences, we can guarantee an average of 200 people staying in your hotels every day as a result of our choosing you as our conference hosting partner', what do you think the reaction would be? If ACM then has a handful of people who can arrange the AV and ensure that there's a consistent presenter experience and recordings make it into the ACM DL immediately, that would be a huge win.
Let academics focus on the content of the conference, no on the logistics.