I don't remember I find such a Formula, but it's always worht the effort to visit each trader each level (they restock items).

What I always did in my previous play :
searching for weapons with that encantment on it and if that weapon isn't what I wish to use I DISenchant it and use the learned formula (via disenchanting) on my favorite weapon wink

I find more good/needed enchantments on gear than I find the Formula itself somewhere or by a trader.

After taking over the Battle Tower it's worth the effort to first search for 3 different parts of a Zeppelin to give to Page at the Champion Harbour, so you can fast go to Aleroth where you can trade with at least 2 very good traders !
And make a study of all the Blue Teleporters is also worth the effort if you like to trade and go fast from place to place !

Just my thoughts smile



On 7th of february 2015 : I start a new adventure in the Divinity world of Original Sin,
it's a Fantastic Freaking Fabulous Funny ... it's my All Time Favorite One !