This probably violates some permitting requirements or law, but … I’d totally DIY. I did. It’s only as hard as the route you want to follow and the walls you have to go through. And do it right, too — put in a junction box at the end instead of having wires coming out of the law. The job I did was infinitely better than what our cable company had done previously.
If you’re terminating cables, make sure to buy the coax cutter / stripper tool. < $5 at radio shack and worth it.
Only twist is that going through walls can be hard. I had to buy a cable pull tool for the harder runs. But you can also sometimes pull out the existing cable with the new one tied to it. Might be helpful.