In addition to doing the research once every three days, an even better way I've found is to score some Saronite bars and do transmute Titanium every day. I've been doing it for 4-5 days now and I've gotten an "xmute element to element" discovery each day. Additionally, the market (at least on my server - your mileage may vary) is currently flooded with Saronite while Titanium is still somewhat rare, so the Saronite bars are going for 2g each while the Titanium is going for 20+g each - not an incredible profit margin, but enough to ensure that I'm not losing money on the deal (although even if I was, let's face it, a couple of gold per recipe is a steal seeing as how the vendors are hitting 10g each for them at that level).
Sadly, I've yet to get earth to shadow or earth to air yet. Then again, the profit margin on the first is almost nill - earth goes for 5-6g while shadow only goes for 6-7g. Earth to air has some profit margin with air going for mid to high teens, thus meaning around 10g profit a day if I ever get that. I don't see earth to fire on the list http://wow.allakhazam.com/db/skill.html?line=171 though so if your intention is to flip the xmutes, then it looks like shadow to life is the most profitable as life is still going somewhere in the 20+g range on my server.
If you're an xmute spec though, you might want to consider making the different raw meta gems since they've got the highest potential profit if you get a proc.