The Empire uses gold coins as its currency called "Septims" or less frequently "drakes", or even "gold". Since this currency is different than the normal D&D copper-silver-gold-platinum coins, in this post you will see price lists, costs of living and so on. You can use this for any Elder Scrolls game, and not just D&D conversion, or alternatively, you could use it for any game, even not Elder Scrolls by simply changing the name of the coins.
The septim coins are named after the first Septim Emperor, Tiber Septim, who later ascended to godhood and became Talos. On the front side, the portrait of Tiber Septim is engraved into the coin, with the phrase "The Empire is Law - The Law is Sacred", while on the back side a symbol of Akatosh and the words "Praise be Akatosh - and all the Divines"
Septims are circular shaped, and not very big or heavy, one can carry around quite the number of them.
The worth of a Septim
One septim doesn't worth much, only the smallest, cheapest items cost 1 septim. Since there are no smaller value coins, the cheapest items are bought in bulk. For a simple conversion 5 septims equal 1 gold coin in the normal D&D settings with the prices presented in the 5th Edition PHB.
The costs of living
Life is not cheap on Tamriel, food and shelter costs money. Below you will find the daily cost of basic necessities and different lifestyles
Lifestyles and their costs per day
Lifestyle expenses cover your food and lodging for a day.
Poor: 5 septims
Modest: 10 septims
Comfortable: 15 septims
Wealthy: 25 septims
Aristocratic: 50 septims+
Price for food, drink, and lodging
Ale, mug: 1 septim
Ale, bottle: 3 septims
Cheap wine, goblet: 2 septims
Cheap wine, bottle: 4 septims
Common wine, gobletr: 5 septims
Common wine, bottle, 10 septims
Expensive wine, goblet: 15+ septims
Expensive wine, bottle: 30+ septims
Poor meal (stale bread, water, moldy cheese): 1 septim
Modest meal (bread, ale, dried fruits and vegetables, cheese, sometimes dried meat) 3 septims
Comfortable meal (freshly baked bread, meat, fruits and vegetables, cheap wine, cheese, baked potatoes) 5 septims
Wealthy meal (Pastry, game meat, fruits and vegetables, wine, cheese, baked potatoes etc.) 10 septims
Aristocratic meal (Food from rare, exotic ingredients, expensive wine) 20+ septims
Inn stay (per day):
Poor: 1 septim
Modest: 5 septims
Comfortable: 10 septims
Wealthy: 15 septims
Aristocratic: 25+ septims
Weapon and armor prices
Steel and wooden weapons:
Club: 1 septim
Dagger: 10 septims
Greatclub: 1 septim
Handaxe: 25 septims
Javelin: 2 septims
Light hammer: 10 septims
Mace: 25 septims
Quarterstaff: 1 septim
Sickle: 5 septims
Spear: 5 septims
Dart: 1 septim per 5 pieces
Shortbow: 125 septims
Sling: 1 septim
Battleaxe: 50 septims
Flail: 50 septims
Glaive: 100 septims
Greataxe: 150 septims
Greatsword: 250 septims
Halberd: 100 septims
Lance: 50 septims
Longsword: 75 septims
Maul: 50 septims
Morningstar: 75 septims
Pike: 25 septims
Scimitar (curved swords): 125 septims
Shortsword: 50 septims
Trident: 25 septims
War pick: 25 septims
Warhammer: 75 septims
Whip: 10 septims
Longbow: 250 septims
Net: 5 septims
Armors work a bit differently. Instead of material, the armors presented here differ in coverage and assembly. In the brackets I put their D&D equivalent. They are mechanically identical to their DnD equivalent.
Extra light armor (Padded): 25 septims
Light armor (Leather): 50 septims
Reinforced light armor (studded leather) 225 septims
Light weight medium armor (hide): 50 septims
Medium armor (Chain shirt): 250 septims
Piecemail armor (Scale mail): 250 septims
Full medium armor (Breastplate): 2000 septims
Reinforced medium armor (half plate): 3750 septims
Light weight heavy armor (Ring mail) 150 septims
Heavy armor (Chain mail): 375 septims
Full heavy armor (Splint): 1000 septims
Reinforced full heavy armor (Full plate): 7500 septims
(You can see here a description of different armor and weapon materials)
Iron weapons and armor cost half as much as their steel counter parts, but may break on a critical failure.
Orcish weapons and armor cost 1,2 times of the price of the steel weapons and armor, but minimum 100 septims.
Silver weapons cost 1,5 times the price of steel weapons, but minimum 150 septims.
Dwemer and elven armor and weapons cost 2 times the price of steel weapons and armor, but minimum 200 septims.
Glass, Ebony and Dragonbone (after the events of Skyrim) armor and weapons cost 3 times the price of steel weapons and armor, but minimum 500 septims.
Daedric weapons and armor are not available for trading.
Spell tomes and scrolls prices
Spell tomes and scrolls are not very common outside the circles of magic users, but occasionally one can encounter them.
Spell scroll prices:
100 septim + 50 septims X the spell's level.
A 5th level spell scroll would cost 350 septims for example.
Spell tome prices:
50 septim + 200 septims X the spell's level
A spell tome containing a 5th level spell would cost 1050 septims for example.
Scrolls and tomes of 8th and 9th level spells are extremely rare, almost unheard of.