The value of a 50 drachma Greek coin will depend on the design, date and condition.
Precisely $23.56
If this is asking the value of a 1990 half dollar, it's worth 50 cents.
It depends on what kind of drachma you have, but if it is a 10, 50, 100, or 500 drachma, virtually nothing.
what is value
The Greek Drachma is a defunct currency and only valuable, perhaps, as a collector's item. However, given that less than 50% of Greek drachma coins were converted to Euros, the 5 drachma is likely very common and will not fetch any serious value as a collector's item.At the time when the Euro was adopted, 5 drachmae was pegged at €0.0147. Currently, as of 5 August 2016, €0.0147 is worth $0.0163 USD. So, the currency would theoretically be worth this $0.0163 USD at present (less than 2 cents). However, as a defunct currency, it no longer has this worth.
$50
$50 bills dated 1990 and later are only worth face value if you got them in change. Uncirculated ones might retail for a couple of dollars more.
less than 50 cents
It is worth 50 cents. Unless uncirculated and in GEM condition, they have no numismatic value
50 pence
If you got it in change spend it it's only 50 cents