Customisable points-for-weapons scheme
Very similar to the WWP mode, just more customisable.
The biggest theoretical problem I've seen with this is the difficulty of creating a well balanced scheme. The best solution I can think of is to let players edit this scheme in the same way we edit any other scheme, with the addition of being able to change how much each weapon costs and how many "coins" are available.
In this way we wouldn't have to wait until a new beta update in order to play with a different "points for weapons" scheme. Or there could be leagues with a different scheme each season, and the player that finds the best combination for that scheme faster will probably be on top. Also eventually people could find more than one well balanced scheme.
I know there are some problems, like the fact that you would have to re-edit your team when a new scheme is loaded (different costs, different coins) but maybe this could be solved with a scheme cache and a new menu inside the team options where you could select each scheme and adjust your team stock for each different scheme. Then when you join a game, if the host selects a scheme that has the exact same settings as one you have, the stock you previously built up for that particular scheme would be automatically loaded. On the other hand, if the settings selected by the host do not match any of the schemes you have, you would receive a notification.
Besides that, problems like "ah, but it would take a lot of time to build up your stock if the host selects a new scheme" are rather insignificant considering that all the leagues and tournaments let you download beforehand the scheme that will be used.
This is a really nice idea. However, I have some suggestions:
I don't think that the bought weapons should be stored in the team settings. Instead, when the game is about to start, the players are presented with the "buy weapons" screen. This window should be designed so that buying weapons is simple, and when playing the same scheme multiple times it'd be easy to buy the same weapons as usual. For example: the icons of all available weapons are shown, with the price tag under them. When you click a weapon, it is added to your inventory, at the bottom; you can remove them by clicking on them there.