Caesar had to, even considering the huge amount of money he paid for the land, improvise a little when constructing his forum. These are the remains of shops on the south side.
"We behold with admiration pyramids that were built by kings, when the very ground alone, that was purchased by the Dictator Cæsar, for the construction of his Forum, cost one hundred millions of sesterces! If, too, an enormous expenditure has its attractions for any one whose mind is influenced by monetary considerations, be it known to him that the house in which Clodius dwelt, who was slain by Milo, was purchased by him at the price of fourteen million eight hundred thousand sesterces!"
Pliny the Elder - Naturalis Historia (the Natural History) XXXVI.24
Translated by John Bostock, H.T. Riley