You may have noticed that in version 0.7 there are no new science packs. This is intentional as I was starting to feel like there were too many for both me as the developer and the player. Replacing all 4 types of science pack every tier was just too much to keep track of as well as too much to refactor the production of every tier. So I have made the change in the next build that science will only go up every other tier. For example the Iron Tier will have a new Structural science pack as well as the introduction of chemical but will not have a new mechanical. Steel will have a new Mechanical and introduce electrical (when it gets added to the game) but will not have a structural or chemical. This alternating pattern will continue up into the higher tiers. This means that instead of the potential 18 science packs it is down to only 10 which feels a lot more manageable.
I have also reduced the science costs for most techs by about half I was a little too aggressive in the rate of increase I believe. With the change in level of packs adding to the cost of things as you go higher as well as number the number of packs does not need to be as high as one might think.
I have also removed the repair pack item as they just were not working how I wanted and I couldn't find a good way to make them work. The ability to repair buildings has been moved to the wrench and it fits in quite nicely as you can't remove damaged buildings anyways. currently it cost 1 wrench durability per 100 HP but this could always change.
All of this and more will be in the next build hopefully coming out Friday or Monday.