Good question Green. I believe you are absolutely correct to assume that this is a very new creation all around. You have answered part of your own question. If the price is relative low you can be fairly sure you are not dealing with a real antique. And though there are, indeed, some old examples of complex pamors like thus Bonang variety, super complex pamors are far less likely on most truly old keris.
It is the style to add some "aging" to brand new keris in Jawa AFAIK. This is not necessarily done to deceive. It is just the way people like their keris to look even when they realize they are buying a brand new piece. Unfortunately, many unscrupulous dealers try to pass these along to unknowing collectors as old keris.
There are some artificially aged pieces that have actually fooled experts, even upon close examination. It's hard to pass along tips to how to avoid getting fooled, especially if all you have to go on is a photo on the internet. Or at least to put it into words. There are certainly keris i have looked at on line that i can almost immediately say, yes, that is definitely a newly made aged piece. Often it is the way the wear has been applied, the evenness of the surface wear, etc. Sometimes it's just a matter of the type of iron used that just doesn't come across as old. Sometime the pamor doesn't look quite right for the supposed age of the keris. Of course, modern smiths have been know to use old keris to forge from so judging the materials can sometimes be deceptive.
My best advice is to find a knowledgeable dealer or two that you truly trust to make most of your purchases from and understand that when you buy from other sources such as eBay auctions that it will always be a bit of a crap shoot.
Hopeful others here can put their ideas about this into words better than i can. But the more keris you look at, both old and new, the more you come to an understanding on how to feel the difference out...at least sometimes...
