I would agree the Gold Dollar is not the best choice for a beginner; however, the OP has stated he is knowledgeable about knives and I am assuming he knows how to sharpen a knife and owns some hones. Anyone who can sharpen a knife can sharpen a straight razor - the only thing that remains is learning how to achieve the final refinement. That last part is very challenging; however, it is no easier with a $500 straight razor.
I have to chuckle a little when I here that anyone who can sharpen a knife can sharpen a razor. There have been quite a people who joined a dedicated straight razor forum that I belong to that blithely assumed that because they can sharpen a knife doing a SR would be no problem. Quite a number have posted later asking what they are doing wrong because they can't get their SR to shave comfortably. The two skill sets are related but not identical.
I don't know squat about sharpening a knife but have to ask if most people who sharpen knives have 1k, 3K, 8K and 12K hones?
I do not think shaving with a SR is a cheap hobby and the learning curve to be able to shave with a SR can be long and frustrating. Not trying to discourage anyone just saying go into it with eyes open. When you do get it all together shaving with a SR is a very satisfying experience, at least it is for me.
Anyway good luck to the OP.
Bob