I hate to be the bearer of bad news, but the truth is that the Boker version is the reasonably priced copy. With the exception of the short-lived Blackjack model, every previous rendering of the Applegate-Fairbairn has been significantly more expensive than Boker's. And you can't find the Blackjacks for less than the Bokers these days.
If you're only looking for a cheaper substitute, those recommended thus far are all good suggestions. You won't have much trouble finding inexpensive daggers. But if you want the real thing, with all of its accompanying design elements, you won't go wrong with the Boker. I don't know which reviews you're looking at, but Boker makes fine knives, and the A-F is no exception. Functionally, I'd say it's the equal (or better) of any production version made prior. Aesthetically, the Boker is no slouch, either, with lots of interesting variations over the years.
Since you're interested in the A-F as the real knife to correspond with your training knives, I think you'd be well served saving up for a Boker. Why would you skimp on a fighting knife?
-Steve