Check brickseek.com to look for a deal at your local walmart on the 560. They are on clearance this time of year. I found one a few weeks ago for $275 and then a few days later a different walmart in the area had them for $150. If you can find one on clearance its worth giving a try. For me at $275 the "quality" issues dont bother me. This thing is built way better than any $275 grill I've every seen.
I also have an 18
wsm with a bbq guru. Look on the facebook market place and you can probably find a used 18
wsm for $100-150 and then you would just have to buy the temp controller of your choice. I found my nearly new
wsm for $125.
These are two different animals in my opinion and both do what they do pretty well. The
WSM is pretty much a one trick pony where as the 560 can grill and smoke. I have used the WSM as a grill but its a bit of a pain in the butt.