I would go so far as to say the blacksmith is obselete at this point.
The jeweler is just over-priced. Leveling to 10 is (if you can't find anything else to spend your money on) a great idea. Maxed gems on a low level character is such a great improvement.
If LLC picks up once we go live with pvp, it will be essential for twink builds.
At this time, its 3 gems of the same tier + gold and the page/tome/++
Once 1.03 comes out, blizzard has been quoted saying the cost will be reduced to 2 of each gem instead of three! You might want to wait for that!
Post Release Update
There was a big blog post today about the the current game design of Diablo III. If you missed it make sure to check it our here. Some key points can be found below, but you really should check out the full post. (http://www.diablofans.com/news/1222-diablo-iii-game-design-update/)
Statistics on builds and other interesting things.
Patch 1.0.2, which has been in development since the game launched, should go live sometime within the next week
In patch 1.0.3 they will be showing the ilvl budget on level 60+ items to make it easier to understand why blues at times are stronger than other level 60 legendaries.
In Patch 1.1 legendaries will be getting a boost. However this will only affect new drops.
Blacksmith will have its gold cost and page cost reduced.
You will only need two gems in order to combine for the next gem, up to Flawless Squares
Hope this helps!