You can sort of already do this with graphite, aka pencil lead, though the conductivity is lower. You can mix powdered graphite and glue to get conductive glue.
Also, I have had a "conductive paint pen" in my lab for 2 years,(and for much less than $50) so this seems more evolutionary than revolutionary. Neat all the same.
PS. My Wife and family are out of town, so I have a little extra free time over the next week or so. My game will go to beta/alpha testers this weekend, and I'll put it on the market within a week or two. I know I keep saying it, but I will post about it then. It has consumed a whole lot of my time, and distracted me from other things that I love. I feel like I am 9 months pregnant and ready to deliver this thing.