I am also wondering why the selection of self starting mercury vapor retrofit lamps in other countries was more limited like in the USA or the EU countries and why the EU decided to ban high pressure sodium retrofit lamps.

Probably because the vast majority of their HID street lighting is mercury vapor, and municipalities want other more energy efficient options that will work on the existing gear without needing to change anything.

While looking at Japan’s HID lighting portfolio, I have noticed that they definitely have an amazingly large selection of mercury vapor retrofit lamps that encompass nearly every HID lighting technology ranging from high pressure sodium, white high CRI high pressure sodium, quartz metal halide, and even ceramic metal halide! Additionally, multiple manufacturers such as National/Panasonic, NEC, Mitsubishi, Iwasaki, and Toshiba made these lamps!! The amazingly large selection of mercury vapor retrofit lamps that Japan offers makes it tempting for me to import them for my own collection. Why was there a need for Japan to design a self-starting mercury vapor retrofit lamp for nearly every HID lamp technology and why did most other countries largely develop dedicated ballasts different from mercury vapor ballasts and external ignitors for the other HID lamp technologies instead of self-starting mercury vapor retrofit lamps like Japan did?

Here is a video that clearly shows the wide variety of mercury vapor retrofit lamps available in Japan if you want to see what the lamps look like warming up:

https://youtu.be/rAfEUeZFNUI?si=sjJJysqTAwcFarUC

In the video, you can see a mercury vapor lamp, a high pressure sodium retrofit lamp, a quartz metal halide retrofit lamp, and a ceramic metal halide retrofit lamp all being used on the same mercury vapor ballast.

Nowadays, LED lighting is known to retrofit nearly every existing light fixture out there in most countries.

Just curious. Are your 50W ballasts CWA ballasts or HX autotransformer ballasts?

Well, it got declined. If this seller ever wants to sell this ballast, they have to lower the price to something more reasonable.

I think I may have two. What would you like to pay for a genuine 50w MV ballast?

Does the usa even have import fees? I've shipped 2nd hand stuff to the usa multiple times but never have had buyers worry about it. The other way round - USA to europe - 21% VAT including over the shipping cost, and if it's above 150 euro in total, a couple percent (about 5 i think) import fees.

Import costs are another barrier to getting ballasts shipped across the world depending on how much they are.

http://www.easycontrolgear.co.uk/BHL-50/80-K407

If you have a 240v hookup at home, and hook this up to the 230v section, you'll probably get close to getting the right current. I haven't calculated it, might wanna run the numbers yourself with regards to the 50/60hz difference.

Alternatively, spend some money on a 230v 50hz true sine inverter.

Update- actually, I think it isn't mercury. The lamp end got a slight teardrop shape. This lamp also seems to have a loose connection, so maybe the cfl ballast is striking it on hot cathode, but the arc remains when the lamp is in cold cathode mode (lamp is shaken and connection loosens). But I don't think this is the case, because my other lamp is also experiencing this on this ballast.
Also, in the picture, the spot isn't the filament structure, as it wasn't there before I lit it on this ballast. The lamp hasn't been running on it for more than 15 seconds.