Total Cost: $5375
Airfare Each: $1045 Icelandair Saga Class (like premium economy, regular economy with seat selection and checked bag $350 less, used 2 checked bags per person as allowed in Saga Class, in addition to 1 checked bag each, checked a cooler greatly used, checked additional bag of warm clothes not needed and 2 bottles wine needed)
Car: $703 for hybrid Kia Xceed (size between Corolla/Civic and Camry/Accord; $88 day w/basic insurance included, used credit card insurance for deductible but not needed), 8 days, Blue Car Rental (nice people and walking distance from Radisson Blu, return at airport one way fee only $10)
Fuel: $188 for Ring Road plus extras like Troll Peninsula, $23.50/day
Lodging: $1525, avg. $170/night (5 nights @ Airbnbs on farms, 1 night Radisson Blu Reykjavik, 1 hostel w/private bath, 1 guesthouse on farm, 1 hotel in Reykjavik suburbs)
Everything else $866: Restaurants, groceries, admissions, airport shuttle, covid tests, parking for Thingvellir, Seljalandfoss, Skaftafell NP, includes $104 for 2 for Myvatn hot water spa (not recommended unless you are a party type, large pool tepid, other pool just warm, only hot water in animal trough shaped thing jammed with young couples)
Like all my recent trips, never used cash. No PIN required at unmanned gas stations. Like Singapore, Iceland can be considered English speaking.
Recommended restaurants Ring Road, counterclockwise:
West of Skógafoss: Gamla fjósið
West of Höfn: Guesthouse Nýpugarðar for lamb dinner
Siglufjörður: TORGIÐ for the lunch buffet
Borgarnes: The Settlement Center for the vegetarian lunch buffet
Nettó (very nice but uncommon)
Kronan (very nice and common)
Bonus (Walmarty, avoid)
Except for eggs, pricing very competitive to USA pricing. All dairy products lactose free, everywhere.