Out of curiosity I spent some time and added these numbers up to know what my trip to Iceland cost compared to previous European trips --
Transportation -- $942
-- United Airlines, RIC-KEF $603, plus $85 to upgrade one (KEF-EWR) leg to economy+
-- Amtrak Williamsburg to Richmond $18, taxi from RVM train station to RIC $41
-- FlyBus with return, KEF to Reykjavík $51
-- Car service from RIC home to Williamsburg $143
Accommodations -- $959
-- 10 nights Loki 101 Guesthouse
Guided Tours -- $655
-- Reykjavík Food Walk $113
-- GeoIceland's Golden Circle, Snæfellsness Peninsula and South Coast tours $300
-- Arctic Adventures' white water rafting and lava tube caving $232
-- Entrance to Hallgrímskirkja tower $10
Unaccounted Cash Spent -- $120
Restaurants -- $178
Grocery Shopping -- $86
Souvenirs -- $91
RIC and EWR Airports -- $54
Previous European trips were all 17 days, and cost between $3300 and $3500. This trip to Iceland was 10 days and came in at $3100.
I am a solo traveler and I would say that I am usually a thrifty traveler -- I'm not cheap and I am not on tight budgets. So on one hand while I'm quite happy to pay for a car service from the airport home, I saw no need to pay for the FlyBus+ service. I was quite capable of walking the half mile from the bus depot to my guesthouse.
And about that car service home, I usually fly from Dulles and take Amtrak to DC. Usually on my return I get a room and stay the night in DC, returning by train home to Williamsburg the morning after. Since I was flying from and to Richmond, I just spent what would have been a night in a hotel on a chauffeured SUV.
On my previous trips I've usually had the majority of my meals in cafes and restaurants. This was the opposite and the guesthouse had a kitchen that I took advantage of. I went for groceries and most of my unaccounted cash spending was for groceries. On the other hand I enjoyed dining a few times at Steikúsiđ and Cafe Loki.
One thing that has stood out to me while planning my trip, was how easily everyone throws out "Iceland is expensive" without ever actually quantifying what they mean by expensive.
I paid more on average for accommodations on this trip than I have previously. But that's rates such as £35 a night for a private room at YHA St Paul's; or £50 a night at Cathedral Gate Hotel in Canterbury; or €70 Hotel Grand Canal in Delft, NL. But! in the scheme of things $96 a night I would still consider inexpensive compared to other options.
For groceries I'd say I spent double what I'd spend at home --
--A box of 3-n-1 instant coffee at Trader Joe's is $2.99, while in Iceland Nestle brand 3-n-1 was 759kr ($6).
--At home a package of either 8 or 10 Oscar Mayer is usually about $4 while Icelandic hotdogs 5 pack was 580kr ($4.60). A package of two hamburger patties was also 580kr.
--A single serving of Skyr was usually around 370kr, while at home its $1.49
--Cream cheese was about 650kr ($5+)
Produce was usually about three times more expensive than at home. Chips and nuts also 3x. Although for bread I was paying the same as at home.
I did not consider eating out to be expensive. Took two meals at Steikúsiđ paying $50-$60, which is what I'd nearly be paying here at home for the same. On the other hand a Subway 6in combo was 1500kr ($12). And while that may be expensive, I was more offended by the $4 bottle of Diet Dr Pepper and $9 sandwich at EWR airport.
As far as my tours and activities I consider what I paid to have been generally in line with what I've previously paid. In Normandy my battlefield tour ran $115 vs the $300 total I paid to GeoIceland for three separate tours.
Those souvenirs? Well I did buy quite a bit of yarn. Paid exactly the same in Iceland that I'd pay at home. Bought 2 pounds of roving too, for $20.
Anyway this was my spending, and for everyone else your milage will certainly vary.