An ATG is worth the cost!!! The initial investment may seem $$$ but it will pay for itself. (When I first started, I spent $70.00+ in my first 4 months) I would recommend buying the 3M ATG. I had both and gave my generic one away because I couldn't see where I was laying down the tape - I am right handed and my friend is left handed. (She loves it!)
If you still would rather use the tape not with an ATG, I like Miracle Tape from Viva Las Vegas (
www.stampo.com) better than ScorTape. The Miracle Tape roll has 55 yds vs. ScorTape roll has 27 yds. The price is also better for the amount of tape on a roll. It is various widths also. You do have to use scissors but I just like this tape better. (There is a thing you can buy to attach to the roll but I still haven't figured out how to use it.)
Good luck on your project.