• Race fee total last year was 1'469 USD
• You can easily find an AirBnB for 2 people for 150-200 EUR / night within 500m of the race start
• Dinner for 2 (3 course + 2-4 glasses of local wine) at a local restaurant will be 80-150 EUR
• If you're staying in Nice, take a bus from the airport - it's 4 EUR per person and takes 25-30 minutes to Nice center
• Not relevant for you, but economy return flight from Zurich to Nice was 180-200 EUR per person, plus 160 EUR for bike transport

For 5 days I spent a tiny bit more than 3'000 EUR for 2 people altogether, and I had a front view at the transition zone (or the sea, whatever is more important for you).

Edit & disclaimer: I'm not generally picky on food and my better half doesn't do French boutique shopping ;)

I don't have specifics, but my wife and I went this past year. We did 4 days in Nice, 3 in Rome and 3 in Florence and flying from Atlanta over was probably 15k. If we only did Nice for 4 days I think the costs could have been closer to 10-11k with 4k of that being airfare.

The costs will be cheaper than Kona for lodging and travel. There is tons of places to stay. We flew direct to Nice from Montreal. The race start is about a 10 minute drive from the airport, at the most.

Consider flying via Paris (many many more flights) and take the TGV down to Nice, and back. Depends on your balance between time and cost.