From next year, the Intercontinental Cup will be a round robin affair between the top 8 Associates giving each team seven 4-day matches. There will also be a final for the top two.
With ODI's scheduled around the I.C matches (which seems to be the pattern at the moment), that will probably account for about as much as the Associates will be able to afford just at the moment. Certainly Kenya, who do pay the squad an allowance while training, plus a match fee, would struggle to pay for more just at the moment.
As the sport grows in the Associates, and I'm sure it will, this could possibly be expanded.
For those Associates who can afford it, I see no reason why they cannot arrange extra 4-day matches against each other without waiting for the ICC.