Updated costs and masses to be in line with stock parts.

[Kerbas-ad-astra]

Looking at the prices (mass and funds) of stock or stockalike parts that provide equivalent benefits to your service module parts (2x Z-100, fuel cell, MRS decoupler, FL-T800 or X200-8 tank, small inline reaction wheels, and QBE), there's been some divergence. I can provide the gory details if you like, but the short version is that the avionics ring needs to weigh less and cost more, and the additional cost and mass of the service module beyond the avionics ring now includes the tank dry masses and costs.

(The research costs could probably also stand to increase, since stock parts have them 5-10x the purchase price instead of 2-3x as you have them, but I haven't played any hard-mode saves with development costs, so I've left them as is.)

[sumghai]

Apologies for the late reply - the proposed cost increases look okay to me.

As for mass reduction, you may need to also adjust the CoMOffset accordingly.

[Kerbas-ad-astra]

Done.

I've also crunched the numbers for cost and mass of the adapter (0.2 tons, 900 funds) and fairing panels (0.1 tons, 200 funds each EDIT: as they already are) to give a 15-20% discount vs. the stock size 2 fairing and TR-18A decoupler (0.5 tons, 1500 funds if the game would just let me close the fairing at the lip of the service module...). Is it alright if I toss that into this pull request as well?

(The shroud's mass and cost numbers are fine.)

[sumghai]

Yep, please do bring in the adapter and fairing cost/mass tweaks too :)

[Kerbas-ad-astra]

Done. Thanks!

[sumghai]

...and merged with thanks :)