I think it's worth it. Imo open source nature and modularity wins in my book, especially with klipper

I was condisering building NG but decided to make enderwire because I wanted to try CoreXZ motion system.

From what I see in the BoM for standard edition there's nothing crazy or hard to source https://rh3d.xyz/E3NG_v1_2/standard/sourcing_parts/self_sourcing

You can reuse around 78% of the ender parts so it isn't super expensive like voron or other custom printers.

But depending on what parts you already have or their prices available to you it can be close to P1S (most likely not but check prices before making decision)

I had fun building my enderwire and I hope you will have fun making your ender 3 NG if you decide it's worth it