Changing the "Research Speed" game option to a value greater than 100 breaks research wealth costs in-game, causing research to consume no wealth at all.
Values of 100 or less function as expected.
Replication: Within any game, new or existing, simply set the "Research Speed" game option to a value greater than 100. Ensure any research project is active and pass at least one construction cycle. Observe the Expenditures table of the Wealth/Trade tab. If this is a new game, you will observe no research expenditure occurring at all. If this is an existing game you will see the amount spent on Research begin to decline, disappearing entirely after whatever time-frame you have selected (1 month, 3 month, etc.) has passed.
SJW: Fixed for v2.6