[0.24] Balancing Parts Prices for "First Contract"

[ultrasquid]

With the impending release of KSP 0.24 with "First Contract", the price of parts now becomes an important element of gameplay. Many add-ons have up to this point used placeholder values for the price of their parts. These will need to be updated. But how do you determine an appropriate price for your parts? That's what I started this thread to discuss.

There should be some relationship between the attributes of a part and its price. A fuel tank, for example, one can calculate its weight and size based on its capacity. Another fuel tank of the same capacity but of greater strength and/or lighter weight must be using more advanced materials, therefore the second tank would have a higher price, and also appear at a later node on the technology tree. A lighter tank would have the benefit of reduced deltaV consumption to move it, so that might be a worthwhile cost offset, especially if fuel expense is ever added to the game.

That's just one example. What are your thoughts?

[falken]

Well the cost of a procedural part is going to be a pain to think about, as is tweakscaled items which are commonplace due to the convenience.

[Mihara]

Actually, procedural parts seem relatively simple. In our world, the cost of a spacecraft component is primarily composed of these components:

1. Development costs. I.e. the cost of designing it. Most of these things are unhealthily complicated, not to mention that it involves numerous prototypes, most of which are not reusable.
   
2. Manufacturing labor costs. Since most of these things are not mass produced, it typically involves exotic manufacturing techniques, stuff that needs to be done manually because there's no machine for it and making one would drive the development costs up even further, or alternatively, it can't be done manually so special machines do have to be built. (Things that are actually mass-produced, like Proton rockets, tend to go down in cost a lot, as most of the development costs are already invested, and purpose-built machines accumulate to manufacture them cheaper.)
   
3. Materials costs. Certain materials used in the construction of spacecraft are exotic, purpose-made, and therefore expensive.
   

As far as I'm aware, development costs are the biggest component, followed by manufacturing labour, followed by materials. I.e the cost of a procedural part is either scaled linearly from a base value, or follows a curve, and the component that changes with size is relatively small, up until it bumps into a structural strength limit and requires a redesign. In theory, costs should depend on your tech level and change with it, or even go down the more times you used a particular part, but I'm betting nothing of the sort was coded.

I suppose we'll have to use stock prices as a baseline again, and I also suspect many of them will be ridiculous, but we'll be obliged to follow them anyway.

[Greys]

There was a tool developed for use with Mission Controller, which procedurally reset part costs based on the part's properties.

How much it weighed, what type of thing it was, what resources it contains and how much, and what partmodules it contained and their configuration. This standardized costs based on mass, materials, and functionality, seems fair enough a method to me; the hard part would be tweaking cost assumptions.

[BudgetHedgehog]

I also suspect many of them will be ridiculous, but we'll be obliged to follow them anyway.

Sounds familiar somehow... You wouldn't happen to have come across any other ridiculous KSP peculiarities, would you?

[ultrasquid]

There was a tool developed for use with Mission Controller, which procedurally reset part costs based on the part's properties.…

Do you know if that tool is still available and where to get it. Seems like it would be especially useful about now.

[NathanKell]

That code is *in* Mission Controller Extended. PartCost.cs unless malkuth has moved it.

[malkuth]

Nope still intact. I did give the user the option to use MCE Part cost or Config file cost a few versions ago though. But code is still intact.

Only major problem I have had issues with it, is ISP and Future engines insane ISP values and those types of engines costing millions of dollars.

seems from the videos that the devs have gone with a much cheaper money system them MCE though. Standard Rockets like the Z Satellite cost about 30K in MCE. Seems with new KSP system that same rocket now cost maybe 8K.

Edited July 16, 2014 by malkuth

[NathanKell]

Hmm, Future Engines should get detected as nukes, right? If necessary you can add another check for Isp > 4000 and add another multiplier?

[ultrasquid]

I haven't been able to get 0.24 to launch on my Mac (something to discuss elsewhere).

Can anyone tell me how the stock part prices stack up, and what sort of price curves we might extrapolate from them?

[Mihara]

I haven't been able to get 0.24 to launch on my Mac (something to discuss elsewhere).

Can anyone tell me how the stock part prices stack up, and what sort of price curves we might extrapolate from them?

http://forum.kerbalspaceprogram.com/threads/86406-Stock-Parts-Costs-and-Balance-Spreadsheet-for-0-24 The spreadsheet therein should be helpful.