You can start marketing with 1k. You just need to start with a small budget and only buy a few items.
You could also sell your inventory to have a better start.
Buy items that sell well, forces and relax for example
trading is awesome. you can find some good trading guides on the tutorial section
Back in 2008 I started marketing with 100-200 TC
And I made and sold millions of TC from them without investing any cent from outside.
The key , like Kriegery said, is to start with tiems that sell fast, ( a good example are force/relaxes and 128 textures)
Also, check the torishop and forum market regulary for good deals.