In my opinion, for a pre-release stage:
Under RuneScape Markets:
Gold Exchange: - Runescape Gold Buying / Runescape Gold Selling / Old School RuneScape
The reason behind the combined section for both, is upon release the number of people buying and selling gold will be miniscule as there will be close to no gold sold for profit. So for a brief period of time threads for both buying/selling can be created in the same section.
Item Exchange: - Runescape Item Purchases / Runescape Item Sales / Old School Runescape Item Exchange
Why another consolidated sub-forum? The number of perishable resources for sale will be close to nothing. When the servers are released people will be focusing on further developing their accounts, and for individuals who do wish to sell resources such as logs/ores/fish/food etc can place up threads in the section where they can request certain items or sell items that they may no longer require.
The next section which involves accounts will barely be used in perhaps the first month of the release starting from Friday, so if a sub-section is implemented, we can just have a whole new sub-forum named "Old School Runescape Accounts" or something along the lines which would cover all accounts on the 07 servers which are being sold.
User Services: -Account Upgrade Services / Skill Training /
Fire Cape, Kiln Cape & Defenders Services /
Questing & Torso Services /
Other Services/ Old School Runescape Services
Everything covered in that sub-forum at the time would include skilling services to questing since people will most likely not be starting a service due to having nothing to do quests with. Skilling services may 'boom' when bots can hook in with 07 scape but until then, it will be run by a small 'niche' of individuals who have time to play runescape all day.
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Since everyone is anticipating 07 Servers to be a massive launch why not create a whole new sub-forum on the main page dedicated 'just' for 07 Servers.
Sub Forum Title: Old School Runescape
- Old School RuneScape Discussion
> Mini-Games & PK'ing
> Free Guides
> Pictures & Videos
- Old School Runescape Cheating
Since most common topics are broad discussions such as account builds and showcasing pictures/screenshots erupt conversations within members there would be no reason not to have it within that set-up.
Once the number of posts and traffic increases to the section, the sub-subforums can be placed straight onto the homepage when more people are actually playing the game, but if you have them all combined upon release, many will get neglected.
Just my opinion, feel free to build on it.