You’ll need a 3 V power source for it. And the problem is that the lockitron moves physically so figuring out how to mount it is going to be tricky without interfering with the ability to manually turn the bolt from inside. (Essential for fire safety.)
I understand the desire to save money but this just doesn’t look like a very practical project to me. But everybody has their own priorities, it will certainly be interesting if you can get it to work! I do wish you luck with it. 
Here’s a little more information on how these are used: