A difficult question.
I generally expect a useful sword to cost over $1K, and the AK-47 from Busse is less expensive than that. If you're fortunate and persistent, given the current economy, you ought to be able to grab one for $700.00.
Unlike most swords or sword-like objects under $1K, the AK-47 is effective 'immortal.' If you should find some way to damage it, Mr. Busse will repair or replace it. His warranty is good; his word is good.
As to function, I and many others here have used an AK-47 to chop objects from the sublime (wet tatami mats) to the ridiculous (pumpkins, hams, tree limbs, tree trunks, and the occasional brick). I recall a few Knuts throwing AK-47s into tree trunks. The factory edge is obtuse but adequately sharp. There are a number of folks around here (Ban comes to mind) who can turn that edge into a razor, if desired. The steel from which the AK-47 is made, INFI, has an excellent combination of "strength" and "toughness" -- it's hard to damage that edge, and when you do, it generally just rolls (fairly easy to steel it back into shape). INFI is not stainless, but I find it is very rust resistant.
Is it as well-balanced and artistically designed as a hand-made katana? Of course not. It is rough and tough and ready for any trouble you'd care to throw at it.
I have handled many hand-forged swords made by master smiths. I might even have a few left locked away. My AK-47s have a genuine place of honor among them.
A few pics for quiet contemplation.
This one is not mine -- it is Tedwca's. I share it to show you a 'Banned' blade: