Is Mana Vault worthwhile?

I currently have a Nekusar wheel deck, and I am considering getting a mana Vault to put into it.

Here's a bit of background on the deck. The broad strokes are pretty simple...I utilize the card draw to deal damage to opponents and whittle away their life until I can hit hard with a prosperity or something as a win con. I also run Sheoldred, Spiteful Visions and the like the help this along.

I cannot deny that using a card like mana Vault would be useful in generating the large amounts of mana needed to accomplish this particular goal. However, it occurs to me that for this card ro be truly effective, you also need to run a few cards that will cheaply untap it, to get around the 4 mana cost. Off the top of my head I can think of four, and I would think I would need to run three maybe? A twiddle, a manifold key and one of the wizards maybe?

I found the card at my LGS for like $40.00 CAD, which is on the higher end of what I'm willing to spend. I also will have to pull three or four cards out of my Nekusar deck...

So, people of the EDH subreddit....is it worth it? Can I work it? Can I put my thing down, flip it and reverse it?