First off, I personally will always recommend a Laser over an inkjet unless color is needed, and then, will consider other options like a Xerox Phaser 8400. As for your toner causing the line, that is typical. It could be that the photo drum (the blue green roller) is defective, but the most common cause I see for this is that the cartridge is running low and needs replacing soon anyways.
Being part of a company that does service HP, Lexmark and Xerox printers, I get called out on many service calls for this exact problem. Always gives me a smile when I show up and tell them that it's the toner causing the problem, and their printer is fine. Typically, it's the fastest $95 you'll ever make. (that is our minimum onsite charge)
One thing that you can do to verifiy if it's a cartridge problem next time, on most image defects, is to do what HP calls a "Half Test." Basically, you'll load paper into the MP tray, or Tray 1. Usually, this is a drop down door on the front of the printer. Get the printer to print something. Once the paper gets almost all the way into the printer, open the top cover. You can then check the toner cartridge for the defect, and also the paper, and see if there is a defect.
If the defect is:
1. On the Toner, it's a bad cartridge
2. On the paper but NOT on the Toner, it's the Transfer Roller. (the long black roller under the toner cart.)
3. If you don't see it on either the cartride OR paper, it's the fuser. (the heating elemant)
Timothy N. Couch
A1 Printech
Anchorage, AK