I would go for the Ryobi too.
I used to go around the neighborhood on garbage day and look for gas trimmers etc being put out as trash. Most all just have problems with the powerhead, and the engine works OK.
Thus I got them for free that way. But you need to go around early before the metal scavengers come around to get them too.

Some of the small engine repair shops have piles of the things out back too. They'll usually give you one or two or maybe for a small pittance in cost.