Professor Egghead's Horse

Professor Egghead bought a horse for 60 Euros.  He later sold the horse to his neighbor for 70 Euros, but discovered that he could have made a better deal.  The professor borrowed 10 Euros from his wife and repurchased the horse from his neighbor for 80 Euros, which he then sold to a different neighbor for 90 Euros.


How much money did Professor Egghead make through his transactions?