I can get a g-loomis rod blank for around 100$ how much more money and work would need to go in to it to make it the basic rod i can fish with. and what is the thread for? they sell

It all depends on what guides, how many, what type of cork, reel seat, wraps, ETC... The thread is for wrapping the guides... is that what you're talking about? It could be another $100 or more depending on components (high dollar guides) and whether you build it or are having someone else build it for you.