This is what Suetonius reports:

In his last will, however, he named three heirs, his sisters' grandsons, Gaius Octavius, to three-fourths of his estate, and Lucius Pinarius and Quintus Pedius to share the remainder. At the end of the will, too, he adopted Gaius Octavius into his family and gave him his name. He named several of his assassins among the guardians of his son, in case one should be born to him, and Decimus Brutus even among his heirs in the second degree. To the people he left his gardens near the Tiber for their common use and three hundred sesterces to each man.

Three hundred sesterces to each male citizen is A LOT!

Herz in Brill's Companion to the Roman Army estimated a legionary under Augustus made about 900 sesterces a year. Brunt in Italian Man Power (guess what I'm researching to have these on hand?) estimates in 28 BCE (after the second Civil War) something around 1.5 million male citizens.

That's something like 450 million sesterces. Given that legionary pay works out something close to 3 sesterces /day, if I'm doing my math right and I often don't, Caesar gave away something like 150 million days' wages, so something like a little less than half a year's income for everyone? (please tell me I did math right!).

Obviously this involves some estimates as to population, and there's almost a 25 year gap between Caesar's death and Augustus' census, but it's just as far back to the census of 70 BCE and Brunt estimates just about a population of 1 million then, so at least it's not an order of magnitude off.

I have no idea what the value of "the estate" or the gardens was, but apparently the gardens were a big deal.