US: (note: Region "A" discs for North America)

• 1.11 (Out of print, typically $50-$80 used on eBay)
• 2.22 (Out of print, typically $10-$20 used on eBay)
• 3.33 (Still in print, available directly from Amazon for $22)

UK: (note: Region "B" discs for Europe / Australasia)

• All three films are available at retailers like HMV and Zavvi for under 10 GBP each.

Assuming that you're in the United States, here's the current status for Rebuild Blu-rays:

• 1.11: The Funimation Blu-ray release has been out of print for several years, and the going rate on eBay for used copies is roughly $70.
• 2.22: The Funimation Blu-ray went out of print recently, but can still be found new at Best Buy for $23. Used copies on eBay can be found for less than $20.
• 3.33: The Funimation Blu-ray is still readily available from multiple retailers (Amazon, Best Buy, Right Stuf, etc.) for roughly $25.
• 3.0+1.11: Blu-ray release coming to US store shelves later this year via GKIDS. It'll probably be nearer to the end of the year though, as the Japanese Blu-ray was only released earlier this week.

Note that there are not any US box sets of the Rebuild films either.

So if you want to do it in Order first watch the original series NGE.

The ending is pretty out there (VERY meta), and doesn't answer a TON of questions. Thus a lot of fans were pissed so they made 2 movies that "re-wrote" the ending, they are Death and Rebirth and end of eva.

THEN, a bunch of years past till recently and it was decided to distill the ENTIRE series down to 3 movies and change a bunch of stuff. These movies are why the collab came along and it's basically a distilled version of the series without extra fluff and some differences in characters, story flow, etc. these are 1.11 - 2.22 - and 3.33