Reddit reviews Puella Magi Madoka Magica Blu-ray 1

If you want to "finally support my favorite series" then there's no way around buying them new. They don't earn a single cent from your used purchase.

The Japanese series Blu-rays don't have english subtitles, only the 3 movies do.
So if you insist on having english subtitles on the Blu-ray then you'll have to get the US or UK version.

The UK version is available cheap as a complete set but it won't work on US players:

http://www.amazon.co.uk/Puella-Madoka-Complete-Collection-Blu-ray/dp/B008MJRO6O/

The US version is only available as 3 separate Blu-rays, each twice as expensive as the complete UK version:

http://www.amazon.com/Puella-Magi-Madoka-Magica-Blu-ray/dp/B00771V6OY/

http://www.amazon.com/Puella-Magi-Madoka-Magica-Blu-Ray/dp/B007S0PJTW/

http://www.amazon.com/Puella-Magi-Madoka-Magica-Blu-ray/dp/B0089X92LI/

It's simpler with Rebellion. There's only the Japanese Blu-ray available yet so you only have two decisions to make. Standard or limited and where to purchase from.

http://www.amazon.co.jp/劇場版-魔法少女まどか☆マギカ-叛逆の物語-通常版-Blu-ray/dp/B00I9YND9E/

http://www.amazon.co.jp/劇場版-魔法少女まどか☆マギカ-叛逆の物語-完全生産限定版-Blu-ray/dp/B00I9YNB4Q/

http://www.madokamagicausa.com/rebellion/


You can also search on play-asia, yesasia and the likes to see if they offer it and what they charge. Don't forget to inform yourself about possible import taxes of your country.