big skimmer requirements buy or DIY?

[ScubaSteve]

Depends on what you are trying to achieve. I often find that a DIY project offers more in the value of feeling like you did a damn good job and built your own stuff, rather than in cost savings. Bare in mind that manufacturers get a far greater discount on materials than we do.

That being said, I love DIY so much that I have my own CNC mill just to make fun stuff.

I think the better route would be to figure out the skimmer he wants and them do an eBay search, CanReef search or BCAquaria search to see if you can find a used skimmer. Probably get better performance for your $$$.