Look at the exceptional coin in our main picture (to the left). It's an Octavian denarius (about 3.7 grams, about 18 mm diameter) in wonderful shape. It comes from Roma Numismatics in London where it sold for 700 GBP (about $1100 US dollar) during a 2015 auction.
The coin in our secondary picture (to the right) is much less desirable. It's a $50 coin. From this you can get an idea of value:
worn: $50 US dollars approximate catalog value
average circulated: $350
well preserved: $800
Here is the description from Roma's auction:
Octavian AR Denarius. Rome, 28 BC. Laureate bust of Apollo of Actium right, with features of Octavian / Octavian, veiled and in priestly robes, ploughing right with team of oxen; IMP•CAESAR in exergue. RIC 272; BMC 638; RSC 117. 3.66g, 18mm, 4h.
Good Very Fine. Attractively toned.
The obverse of this rare coin borrows from the Greek tradition of moulding the features of a deity to resemble the ruler, as was the case on the coinage of Alexander and his father Philip. The reverse depicts Octavian as city founder of Nicopolis in Epirus, established in 31 BC at the site of the battle of Actium in memory of his victory over Antony and Cleopatra. The sacred boundary was marked by a pomerium or sacred furrow. On the spot where Octavian's own tent had been pitched he built a monument adorned with the beaks of the captured galleys; and in further celebration of his victory he instituted the so-called Actian games in honour of Apollo Actius, who had an ancient temple on the promontory there.
Estimate: 500 GBP