Tweak the price of all science research technologies including infinite ones by a global decimal multiplier. For example, a multiplier of 0.5 means technologies cost half as much and thus take half as long time to research.

The difference between this and the native option (found when creating a new game) is that it supports decimal factors, so you are able to reduce the price (0.5 for half) or increase it slightly (1.2 for 20% more expensive).

There is also a multiplier for the exponential growth of the price of infinite technologies. Setting that to 0.5 means that the prices will increase half as much per level. Setting it to 0 will remove the growth entirely, making the higher levels cost as much as the first level.

They default to 1.0 (no change). Tweak the values in the Startup tab in Settings > Mod Settings from the main menu.