One of the (many) frustrations in looking at the classical world is that it is so difficult to get any idea of prices and purchasing power that make sense in the modern world. There is certainly no such item as an average shopping basket.
Take this set of accounts from Brian Campbell's The Roman Army, 31 BC – AD 337, (London, 1994). It is of an auxiliary soldier stationed in Egypt from the second half of the first century:
Gaius Valerius Germanus from Tyre received the first salary instalment of the third year of the emperor, 247½ drachmas out of which
Deduction for hay 10 drachmas
For food 80 drachmas
Boots, socks 12 drachmas
Saturnalia of the camp 20 drachmas
For clothes 100 drachmas
Expenditure 222 drachmas
Balance deposited into his account 25½ drachmas
Already had 21 drachmas
Makes a complete total of 46½ drachmas
It is not easy to put the 250 sesterces salary payment (drachma were on parity with the Roman sesterces – the 2½ drachma deduction presumably a currency exchange charge) into a context that is understandable today. The 46½ sesterces that Germanus had in his account was the equivalent of 465 asses, the bronze coins in common usage. To give some indication of purchasing power, a litre of good wine cost four asses, a week’s worth of grain around twelve asses.
We do, however, have a fascinating set of comparative figures for the price of grain from the end of the fourth, beginning of the fifth century.
In Ravenna at the end of 492 AD, a gold piece bought you just under three pints of grain.
In the middle of Theoderic's reign, say a decade later, there is one reference to a price of 960 pints per gold piece, though the more usual (Ep 27) rate was 400 pints per gold piece.
Even though the figures are extreme - the first figure is from a city at the end of long siege, in a country that had suffered several years of warfare - grain is a particularly handy indicator of stability in this period. To grow it, farmers need to be sure at the start of the year that their fields are not going to become an battlefield come harvest time.
Little wonder then that Theoderic's reign was deemed a golden age.