As we wait for ManiacQuilter2, I just wanted to let you know (in case you were unaware) you cannot upgrade from EQ4 to EQ7. You had mentioned upgrading if you find you like the program, which is why I'm saying this. Electric Quilt will only give you the upgrade discount if you're going from EQ6 to EQ7.
Having said that, it's entirely possible you may find a used copy of EQ6 around somewhere. Check your local quilt shops, guilds, and groups such as Yahoo's "sew it's for sale". I bought a used copy of EQ7 for my mom at a very reasonable price and had no problem getting it installed and activated.