One power focus (singular) or several power foci (plural). Just like one stadium, medium, datum, criterion, forum and several stadia, media, data, criteria, fora.

That depends on the game you play. Yes, most tabletop games, you won't have really high skills because of four reasons I can see. One is the retirement of characters due to boredom, second being the lack of karma in some games to have people wanting to focus on one skill enough to get to high levels, third is the lethality in some games, and the final one is the fact that games that go by the books do cap 8 as the top level skill.

However, I've seen some games, a few TT Games, but mostly in the electronic versions the Shadowrun MU*s where people don't really follow what the book says and, since it is almost a living entity in the fact there's always something going on, some people have a lot of karma to get skills up to 12 or higher. There was one person I saw with a pistol skill of 14 at one point.

Personally, I don't like it since it means that the game just becomes either a cake walk for them or so difficult that other people get disinterested. For example, a PC with maybe 5KP, 7CP and a body attrib and pistol skill of 6... With some good armor, they could take out a gang of five or six people themselves easily and may take a few wounds themselves. Someone with a KP of 20, 10CP, body attrib of 12 and a pistol skill of 14, they could probably take on a gang of like ten to fifteen easily on their own because even with TNs of 6, 8, 10 they statistically have a better chance than someone else.

Anyway, to make a long rant shorter, some games can have the higher skills for different reasons, and if they do, then their worlds tend to change for it. It is almost like a Monty Haul campaign in D&D.

As for the costs of the 'think tank', I would look at money in your campaign as well. IF you want to take money away, that's a good reason. But as for how I would charge them myself, it would depend on what they are looking for. Knowsofts, sure they're good but they're only as good as the people who made them. Not to mention supporting skills and also pools adding to anything you do. Sometimes, natural skills are better in that way, at least to me. But as I said a couple times, it's your world, they just live in it.

Talismongering isn't a magical skill, though. Enchanting is; you can't learn to create a focus from an activesoft. But talismongering is just gathering materials for use in fouces or magic, and you can get that sort of information out of a book. Really, talismongering is just a knowledge skill: you know what components are used in common magical procedures, and you know how to collect them properly.