I bought a Ryobi weed wacker just like this about three years ago to clear my lots. It has a metal blade to cut bigger stuff but soon found out it wasn't strong enough for anything but small stuff. Shortly after the pull start froze up. In the last year two tuneups were required including a carburetor rebuild.
Last week after the rebuild I was ready to cut my out of control grass and after 5 pulls the start cable jambed in the out position. I took it back to the rental/rebuild guys and asked if they wanted to buy it. I got 500 pesos and a free rental of one of theirs. One less headache for me and I'll continue to rent ... but not that Ryobi!