additional processing and customs charges on goldring 1006 or nagaoka mp150

@jcarr 

It is true that in the first part of the 1970s JVC focused on MMs, but after JVC launched its first MC cartridge, the MC-1 direct-scan design in 1977, they focused on this family as their flagship range.

http://20cheaddatebase.web.fc2.com/needie/NDVICTOR/MC-1.html

These JVCs are the spiritual ancestors to the modern Audio Technics ART-1000.

As you point out, most of this family used beryllium cantilevers, although duralumin was also employed.

Right, and the Victor L-1000 was the best one with printed coil right above the diamond, but most of them have a very short life. I don't know if it's easy to fix those cartridges (maybe you know better), but most of them have a problem with one channel or with both channels even if they are looks mint. The price for a used Victor L-1000 dramatically increased after M.Fremer visited Audio-Technica factory in Japan and they said on video what was their inspiration to make AT ART-1000. I wish i could find working Victor MC L-1000 or someone who can fix a non working samples. 

There's just simply nothing better than boron for cantilever material. Japanese got it right. Boron is only 20% denser than beryllium, but boron is 50%+ stiffer.

Beryllium cantilevers only come in a rod form, whereas boron can be made into a pipe. Pipes are potentially lighter and pipes can be made with a wider diameter increasing stiffness even further.

Propagation of sound in both boron and beryllium is similar. 

Aluminum and aluminum alloy pipes are standard. They propagate sound faster than any other less exotic metals such as steel, copper, titanium, etc. Aluminum has low density and can be made into a wide diameter pipe resulting in very high stiffness. Ortofon 2M Black does just that. 

I would imagine aluminum alloyed rods to sound terrible... But I don't think I've ever heard a cartridge with one.

Carbon fiber cantilevers sound very bad to my ears. So do ruby and sapphire. 

@invictus005

Beryllium cantilevers only come in a rod form, whereas boron can be made into a pipe. Pipes are potentially lighter and pipes can be made with a wider diameter increasing stiffness even further.

No, check the Pioneer PC-1000 MKII MM cartridge, it was top of the line model made by Pioneer for their Exclussive turntables, this cartridge comes with BERYLLIUM PIPE cantilever: http://audio-database.com/PIONEER-EXCLUSIVE/etc/pc-1000ii-e.html I got two samples of this great cartridge on hands, it’s a stellar performer!

Here you will see this cartridge on Pioneer Exclussive P-3 turntable, the price for this turntable was 600 000 Yen in 1981 http://audio-database.com/PIONEER-EXCLUSIVE/player/p3-e.html ... And it was more expensive than Technics SL1000mk3 (SP10mk3 with EPA-100MKII in Obsidian Plinth) available for 500 000 Yen in 1982.  

Boron is fine, but always much more expensive than beryllium when it comes to vintage cartridges.

Just because several manufacturers used beryllium for their top models, it doesn't mean that boron is not the ultimate cantilever material. 

BTW, some of your mentioned beryllium cartridges make wonderful sound. 

Boron, beryllium, aluminum... There were a lot of great MM cartridges during that decade. 

 Buy the Pioneer turntable local at a guitar center or other music store because of the loose bearing issues with the arm so you can return it easily.
As other people have said whoever is telling you any cart is hard to install on a DJ turntable is an idiot.  with a removable headshell and overhang gauge that the table comes with you can take your time and easily setup the cart.
Plus vendors like needledoctor and others sell the Ortofon 2m Blue with the SH-4 headshell already mounted.  
later if you want to really improve the table get a KAB silicon tonearm damper.  Amazing improvement in tightening up the bass and dealing with arm resonances.  Several vendors sell the nagaoka mp150 mounted to a headshell pre-wired also.  I was considering that same cart for Technics SL1200G i am looking at.