Roy's instinct told him to get that glimmering spell tome from Farengar. The writing was incomprehensible to him, but he could Observe it.

'Spell Tome: Conjure Familiar

A record of Farengar's experience with this spell. Should you possess an aptitude for magic, you will acquire this spell after using the tome.'

That one was the cheapest in Farengar's collection of novice spell tomes.

"A hundred gold for one spell book. Are you sure that's a good transaction, Goldeneye?" Flynn shook his head in disapproval like he was the one spending the money, not Roy.

Farengar Secret-Fire held the lesser soul gem. "If you don't have the aptitude for magic, that tome would be a waste of money. But if you do have the aptitude for it, you should join the Mage's College in Winterhold. They'll teach you magic. Systematically."

"He can't understand you, wizard."

"Pity I don't have telepathy."

...