Who build custom rod on this site? I am interested in a St Croix xtreme legend 7 MF. How much would this cost?

Several members build rods, but there is only one who is a forum sponsor.

Look to the right for DVT. Contact Mike. He will take care of you, in top shelf fashion.

That blank is about $180, so add reel seat, guides, etc, and you will have probably $250 in parts.  What the labor would be, I would be guessing, but you'd probably have in the neighborhood of $400 in it.

It is my favorite all-time spinning blank, having made about 5 for family and me.

With a good builder you will have a better rod than factory, IMHO.  You will get what you want in ergonomics, reel seat design, probably better cork, probably better guides, you get to choose the type of guides you want, and most likely better structure from the practice of most builders to not skimp on the epoxy which mounts the reel seat and cork.  

As stated before, contact DVT.