Random research game

I’m trying to create a game where players can only invest in improving their experimentation technology level through research and where experimentation still has a chance to randomly improve all technologies on production.

My inital idea was to disable all technology except for experimentation, that successfully prevented players from choosing to research anything else but also means that experimentation can only improve experimentation on production.

I’m currently creating a game where the development cost of science is high and players starting level for experimentation is 2 (maybe 3). This means that the early phase of the game will have the feel I’m going for, your research direction will be heavily influenced by random chance and your stratergy will have to change to accomodate it, but as the game goes on and player economies grow that ‘feel’ will fade because it is still possible to research all technologies.

Can anyone else think of a way with the current settings to impliment this game idea that preserves the random element of research throughout the game?

Is it possible to set a very high custom cost for building science?
I know it’s possible to set a very high custom cost for the trading fee, so all costs are probably customizable
If science cost 1billion to build, the game should finish before someone can afford that