@dononeton
What I am about to say is not against DBPro, just explaining it:
First, everything in DBP is programmed through an external DLL, even all the ADD commands (ShouldBeFour=2+2), and other mathematics. All the casting commands (From an Integer to a Dword) is also done through these external DLLs. There are so many DLLs that they must have a way to communicate with each other, so then there's the function so that DBP knows what is going on.
Next, all of your variables are put into a single block of memory, so whenever you access these variables, one of these DBP DLLs must retrieve your variable from that block of memory, and pass it to the function, or the DLL being called.
Finally, there is a good chance that a large portion of DBC (The original Dark Basic, which was interpretted) was ported into DBP, you can even tell this if you look through the DBP DLLs, you can see some of the old DBC functions which are no longer supported, they are probably provided to let you know they aren't supported, but, whatever the reason, they are still from the old DBC. And of course, all of this was done in C++ to begin with.
Now then, if you want to use PurePlugin, I have nothing against it, by all means buy it, it would help out Freddix, if you choose not to, I can help you out along the way to building plugins with DBP, if you happen to finish one, I wouldn't mind showcasing it in this thread.
Cheers,
-naota