Agreed.
But... To be truly balanced, we need to be weaker at weaker levels. I, for example, didn't find any substantial reason to raise my skill above 60. Don't know how low this goes post patch, but I never had a reason to raise the skill above 50. And that bothered me. So a Skillcap raise or a skillpoint cost raise could solve the problem.
This I can agree with. I often delay raising any of my combat skills until certain non-combat ones are capped, and even when using weapons that have a skill requirement of 75 or 100 while my skill is, say, 40, I don't really feel the penalties doing so imposes.
Not fond of the skill point cost increase idea, despite it accurately mirroring the fact that the better you are at something the harder it is to improve in that area. It wasn't even needed in FO2, as raising even one skill to the 300 cap would have taken over 250 (125 for tags, as they raised at a 2:1 rate) skill points and you weren't going to max more than a few even if you managed to grind to the L99 cap. The 5 skills that had magazines would have needed less, since you could get them to 100 with those before putting any points in, but even then that's still a 200 (100 if tagged) point investment to cap one of those skills. It didn't help that, aside from the Skynet quest and it's huge (at least 145 IIRC) Science requirement, there was no real reason to raise any skill much over 100 in the first place.
A skill cap raise I could see, but, as mentioned above, there needs to be a reason to raise the skill that high. In the current system only Lockpick, Science (when applied to hacking), Medicine, and Survival would gain any benefits from going over 100 (the latter two due to scaling effects of related items), and even then you're not seeing much of said benefits save in the toughest of circumstances.
What I would like to see is a return of the FO1 cap of 200 per skill, while retaining the 1:1 increase ratio, coupled with a rebuild of the perk system such that there are perks with really high (i.e. 125 or higher) skill requirements that build on perks with lower requirements of the same skill in order to truly master that particular area of expertise. For example: a Science perk with requirement 150 that allows either the removal of a certain number of 'duds' depending on a comparison of your skill to that of the computer's difficulty rating, or gives one additional allowance reset after you use any provided by the bracket codes, that you would need to have the Computer Whiz perk to get (said perk itself would be completely revamped into something more useful).
For combat skills, have perks of such levels affect things like wear rate or ammunition strength; a master armorer could create custom rounds that are far less deleterious to the weapon they are meant for than someone just starting into making 'home-brew' ammo, especially where Explosive weapons are concerned.