I've been wanting one, but I'm not sure where to look. I'm not sure if buying online is a good idea, or going to a flea market with the hopes of seeing one is. I want your opinion.

Flea Market would most likely be cheaper, but you could walk around for years without finding one. Going online would be more expensive, but you could have one in your hands in the matter of a few weeks.

I've only ever seen broken VB's at the flea's.

Trade offs I guess. 

Yeah, I might just stick to buying from the internet.

Your best bet to find a VB is either off ebay, here on NA, or at a local retro store. You should be aware that VBs have a not insignificant chance of developing eye piece issues over time, regardless of how they were treated by their previous owners. So you should either be prepared to perform DIY fixes, or set aside some cash to have someone mod the VB to fix the problem.

How far do you want to take it? I have a CIB VB with every US game and a couple JP games for sale right now. Instant collection!

Does he need to add water?

I'd advise against it, but he can do whatever he wants with it if he buys it. Or maybe a VB works better after being submerged in water. I doubt anyone has tested this theory.

Funny story because I ran into a complete VB last year(or so) for 20.00 at a flea market.....had every game except for Jack Brothers....didn't come with the box it was in a modified gun case of all things but snug in the foam.... actually talked the guy down to 15.00 because I figured it didn't work and didn't know the value of the games....I was shocked when I got home and it worked....crazy luck I actually traded 4-5 of the games and now want to get them back..haha

He meant the old joke, "Instant X, just add water".

As for the OP, you'll pretty much never find a good working unrefurbished Virtual Boy. Even oven fixed ones don't last that long. My suggestion is to find a "broken" Virtual Boy on purpose because you'll pay less and then have RunnerPack (PVB) or Tiptopjames (NA) solder the ribbon cables for you. A solder fixed VB is an eternal VB.

I knew what he meant. Dry humor rarely translates well on the internet. I don't know why I try.

I've walked the flea markets for several years and have never come across a single VB system. I've only found one game, and it was a Japanese golf game. Good luck!