Now you are putting words in my mouth. 

• I did not say dealers claim that WAAS can be used for planting.  I said that claim came from sites like this one.
• I did not say the 500 was not upgradeable.  In fact in a previous post I think I said that the 500 was very good system.
• You can upgrade a 500 to O* HP and it does not cost $1,000s and $1,000s of dollars.  In many cases the extra expense is money well spent and will easily pay for itself.  But that is a topic for another thread.
• WAAS 1-2" accuracy.  You are the one that keeps bringing that back up.  I have not heard one thing about it.
• RTK systems are not as expensive as you think they are.  There are alternatives to owning your own base station that greatly reduce the cost. 

Again, I do not take this discussion personally.  I have had people disagree with me before.  I just think that the entire picture needs to be presented.  You have presented your side.  I am trying to point out that your experience will not necessarily be what others will find if they try it.

Have a good day.