There are really four types of replicas out there that I know of.
There is Noble Collection, who did only a few items, and their quality is.. well.. not considered the best. There are also some issues with scale if I remember correctly, however I can't say, because due to all the negative comments from other collectors that I read back in the day, I didn't even bother with the noble collection weapon replicas. I liked the appearance of the axes, swords, and other items much better when it came to United Cutlery. HOWEVER, noble did some great replicas of the other props. I love their jewelry and have the ring of barahir, the evenstar, the crown of king elessar, the elven brooch, etc. Love them all. But yeah, I would be weary of the swords from noble. Price wise, they are also crazy. Sting from them is 300 plus shipping.. which is about what I paid for my MUSEUM COLLECTION sting from UC. Which is.. amazing. And it looks to me like on their site right now, only sting and the axe are on there still. So the other items are probably even more expensive to track down.
Knockoffs. You can find knockoffs for anywhere from 25 bucks to 100 bucks and up. Be careful if you want to avoid these. People try to trick you. You have to make sure if you want a UC sword that it says UC and they should mention certificates, or should show the boxes, the etchings on the blades, etc. Fake knockoffs are not all horrible. I've seen some good ones for decent prices. But there are also a lot that are atrocious. It's a toss up. Most of them tend to be held together with some super glue, plastic threads, cheap crap like that when you break them open. This does not bode well for how they will hold up. The difference that really bothers me is the VERY bright shine to the metal most knockoffs use. It is blinding. UC swords are shiny, but they have a wonderful stainless steel look. Most knockoffs are like mirrors, and you can see yourself in them pretty clearly from my experience.
Then you have what most of us collect. The UC items. United Cutlery produced a HUGE amount of the swords, shields, helmets, etc. They are usually pretty faithful to the props, and decently priced for what you get. Some of the rare items like the shards of narsil, LE anduril, museum sting, and museum glamdring are very hard to track down, but can still be found for a high price.
Most of the UC items have rat tail tangs. Which is common for wall hangers. These swords are not to be swung, or battled with. They are purely for display. It wont hurt to usually wave it around gently outside for a bit of enjoyment. But slashing, hacking, or fast movements, even in mid-air, are going to be bad for these. They can loosen, they can break the thread inside the pommel or wherever it happens to be attached, and fly off and kill you or a loved one or fido. So don't do it! I take mine out every once and a while and play around. I have been known to hold Anduril in the moonlight of the full moon just to gaze upon the ruins and the light shining from the blade. A few soft "swoosh swoosh"'s and i'm all done. I wont risk it! So if you want something to swing around, and/or use for a fanfilm, the knockoffs are great, as long as you are aware that they will break pretty easily and becoming whirling shrapnel!
There are a few items from UC that are not rat-tails. Legolas's knives I think are full tang.. sting maybe.. the uruk blade obviously is just one hung of metal.
Then you have the museum collection UC swords. The newest was Sam's museum collection sword from weathertop. Don't. Not a true museum item. It's made of the stainless steel the other swords are made of, and is unworthy of the title. The only TRUE museum collection swords they did were Glamdring, and Sting. Both came with big glass display cases, nice COA's, made of carbon steel, full tang i think, and very top notch quality for a replica. They are also weathered a bit. I only have the sting MC, but I love it. Very nice item.
Then there are the weta swords, that are like 10 per run, and cost 10,000+ most of the time. A few people have those on here. And I want to punch them. Because they are lucky, and i'm jealous, and wants the precious too..
So there you are. a short history of what is out there, as far as I know.
What did I miss everyone? lol