I'm glad the Millennium are trying to do something to spice up the game, and I can kinda see where they are coming from with this idea, although I see a few potential holes…
Seems to me they are trying to cut out those few minutes of paint static slinging that you get in most points where the teams break out evenly with 5on5 (or even 4on5) and cut to the chase of getting the point closed out almost instantly. Tbh the games in Europe have never been quite as much of a paint slog as some of the PSP games I've seen on the PBA webcast, but it does happen (I once watched a 15 minute double OT point in the D1 semi finals at Chicago a few years back). The flip side to that is that I feel you need that minute or so of jockeying and figuring out what the next move needs to be and how to make it happen. They are selling it as a 'skill' to be able to play with less paint, personally I;d say shooting and maintaining a good lane are two separate and very valuable skills for a paintballer, but equally so is being able to force the issue and win the point. With this new format you're getting very close to the whole thing being a series of reckless (and pointless) run throughs OTB. Great for car-crash music video style edits, not really much of a game though.
Having done some number crunching, most teams do seem to use somewhere in the regain of 1 box of paint per point they play (going off my own teams consumption and anecdotally from others) so given that this allows 2500 'balls in play' for every point, in theory this should not alter that hugely - the trick will be having the right amount of paint with the right people at the right time… Although just by putting this limit on, it will ultimately reduce the amount of paint teams shoot at events the same way as lowering RoF has. Will it half the average paint bill? I doubt it. Maybe at first as teams play recklessly as an overcompensation for the lack of paint on their back - not many players are happy to sit and keep shooting a lane when they have only one pod left, they try to make something happen, then they normally get shot still with that one pod in their pack.. But teams and players will quickly find a more natural rhythm to it and it will settle down.
As Mike said, I think it will have some refinements made before it goes live, and if they are smart enough to make it X amount of pots between the live players rather than 2 each you might see something like 12 pots between 5 players in CPL or something, just to give the game a bit more depth and allow the points to play out a bit more rather than always coming down to who runs out of paint first.
Ultimately though this is about bums on seats - will this change open the Millennium up to more teams…? Yes, but not by a huge amount.
Will the over all cost of attending one go down - yes, probably, but not by a huge amount assuming entry fees, travel, hotel etc remain will largely unchanged.
Will the national leagues all follow suit and thus become even cheaper to play than they already are - yes, and they will probably see a bigger growth / retention of teams than the Millennium.
I still maintain the biggest barrier to teams competing at the Millennium is the field layout release. If the teams are not pressured to practise all 4 weeks leading up to a Millennium (spending the cost of attending the event again just in practise) then teams will be more likely to attend. I've heard all the arguments about 'what will the training sites do, what will the CPPS do?' etc and I could give you a fistful of solutions right now to counter that.