I am mostly going to be talking about film cameras but I will mention some digital aspects in this article. When we talk about Japanese cameras there are several and I mean several high quality brands to choose from. Nikon, Canon, Fujifilm, Contax, Pentax, Minolta, Mamiya, Bronica, just to name a few. If you want to get a great quality SLR camera Nikon, Canon, Pentax and Minolta are going to be your best bets. Of course there are exceptions but you can get a great quality Nikon or Canon with a lens for around 150 dollars. However Leica will cost far more and most likely for less function.
The cheapest your are going to find a Leica for in beat up barely working condition will be around 300 to 400 dollars. Most likely this is going to be either an M2 or an M3. These are both great cameras but have no light meter. Then we get into what is really going to cost you, the lenses. If you want Leica lenses they are going to cost you about 400 dollars each for decent quality for their oldest versions. Let's face it. 1950s Leica lenses are good but when you compare it to the 1980s Canon and Nikon lenses you can get for far less, they aren't that great. Also if you want to shoot anything over 135mm Leica is not the brand for you.
The final nail in the coffin is larger aperture lenses. If you have a Japanese camera getting a quick 50 (a 50mm lens with a large aperture) is incredibly easy. A 50mm 1.4 Canon lens FD mount will only run you around 50 dollars and a Nikon about 120. These are both great lenses and finding one in good condition is no problem. The main reason the Nikon will be more expensive is because Nikon has been using the same mount for forever. Even an older lens can be easily used on a modern Nikon digital camera with no adapters. On the other hand is we get an M mount 50mm F1.4 from Leica you can expect to pay 2000 dollars. That's right 2000 dollars. Of course you can get lenses from Zeiss or Voightlander but at that point what is the purpose of owning a Leica body if you are just using third party lenses. You can get Zeiss and Voightlander lenses for brands like Nikon or Contax.
"But I want to use a rangefinder camera!" I understand why people like using rangefinders. It is a completely different creative process compared to using an SLR but there are plenty of good rangefinders from Japan also, like a Canon 7 or a Nikon S2. I would actually make the argument that if you want to spend under 1000 dollars on a rangefinder set up you would be better off getting a Nikon S2. The quality of lenses you will be able to get from the Nikon will be better than a cheap Leica Elmar or an old Summicron. If you want to get an auto-focus rangefinder, cameras like the Contax G2 and Konica Hexar both give Leica glass a run for their money. I would say that the Zeiss lenses for the G2 are some of the best you can get so that is certainly a great way to go. The only downside to the Contax cameras is that they are all electronic and when they break they are basically impossible to fix.
Lastly I want to do a price breakdown of getting a great Nikon Kit vs getting a Leica Kit. Let's go with a budget of $1000.
Let's start with a Nikon F3 for $175, 50mm F1.4 $200, 28mm F2.8 $200, 85mm F2 $268, SB16A Nikon Flash $31, Lastly let's throw in a 75-300mm F4.5-5.6 for $119. Add all of that up and you're at $993 dollars. These are all KEH prices in excellent quality.
Let's compare this with a Leica. We can get a Leica M5 for for $648 dollars in bargain condition. That leaves us with 352 dollars for our lens. The only thing you can get for a decent price within budget would be a 50mm elmar F2.8 for $418 putting you slightly over budget. This isn't a bad set up but it isn't nearly as versatile as the Nikon set up. Why did I choose the M5? Because it is made in Germany and has a light meter giving a fair comparison the F3.
So this brings me back to my main point. Are Leica optics worth the money? Personally I would say no, they aren't at least not for the hobby enthusiast. Of course Leica lenses in the hands of an amazing photographer can produce some incredible images and on the other hand Daido Moriyama produced incredible images using a compact Ricoh camera. With how much film costs to shoot with and developing costs I would say that unless you are extremely wealthy, Leica isn't worth the money and there are better places to be putting your money.