I am running into this same issue. While I bought the Gold license a number of years ago, this is the first chance that we have had to actually be able to put DNP into production. While I've noticed some issues with the Ecommerce (not being able to add services after original plan purchase), I can work around those.
This issue, though, is a complete stopping point. Being unable to take payments kinda defeats the entire purpose of the system. 
Is there some assistance on setting this up for Paypal Standard?
Thank you