Split Science costs between techs and parts, lump nigh-identical parts in same techs

[SorensonPA]

Though currently unimplimented, we know that parts will eventually have a monetary cost for development and that will be unlocked on a per-part basis instead of collectively as the current model. This brings up a bit of an interesting possability: if parts can have a monetary cost, what about costs from other resources, like Science? And if we can give them Science costs, why not split split the total cost of unlocking them between the general principles of the technology and the individual parts themselves?

Let's be frank and honest: given different design philosophies for building and flying rockets, there're eventually parts that people simply don't wind up using and as such they just sit in the catalogue As an example, I never bother with radially-mounted engines (poor TWR) and pretty much everything in Precision Engineering (I make rockets for MEN, not ANTS) and likewise with most of the structural doo-dads like most girders and whatnot. Why should I pay precious, limited Science to unlock them, then? Being able to pay 50% of the current Science cost to unlock it as a pre-req, then apply that Science towards something else or pick-and-choose the bits I'll actually use at additional Science costs will help what I've gotten thus far go even further. And if realism's your big thing, then this idea fits in better as well - you don't suddenly know how to make an internal combustion engine by learning what sort of stuff's flammable and to what degree, you have to conceptualize, experiment, prototype and refine that sucker.

Another, albeit somewhat minor, issue is the way that certain parts that're identical in pretty much all respects are split between different techs. As an example, you start out with FL-T100 and FL-T200 LOF tanks, but have to unlock T400 and T800 tanks through research - but since you can stack the base tanks together as high as you want, and any combo of smaller tanks with the same capacity as larger tanks also have the same mass, the same impact and force tolerances, ultimetily you have to ask "what's the point"? Same deal with 2.5m fuel tanks. In the same vein, some stack bi-, tri- and quad-couplers are spread all over the place while others in a different series are unlocked in the same place. The grounding principles are the same, so why split them up? As it is, by the time you unlock some of them they've become obsolete due to things you unlocked earlier and, as said before, just sit in the catalogue getting in the way.