My 6 weeks walking Le Puy cost CAD$2,500 + airfare. Walking El Camino is an extremely cheap option for extended travel in Europe. 

My Cost Breakdown

Round-trip flight to Paris: CAD$800

I booked round-trip from Vancouver to Paris, though I ended up extending my trip and purchasing a separate ticket home for 35,000 aeroplan points and $105 in taxes (yikes!)

Transport to Le Puy-en-Velay: €47.60

I took a Ouibus bus from Paris to Lyon for €29 (book in advance for fares down to €15), then a SNCF train to Le Puy for €18.60. A direct train would have cost €100.

Daily living expenses: €18 to €38

Chambre-d'hôtes (B&Bs) are €30 to €33 a night for dinner, breakfast and a bed. I would buy snacks and a sandwich every day for €3 to €5. My daily spending on the Le Puy route was higher than the minimum you can do. I considered authentic French cuisine an essential part of my Camino experience so stayed mostly at B&Bs.

Gîtes (hostels) are €8 to €15 a night for a shared room, with personal groceries for three meals costing €10 to €15. I stayed in hostels a bit more as I got comfortable with my French and daily routine.

Unclaimed medical expenses: €80

Blister covers and creams were an unforeseen expense of the Camino and unfortunately not covered under my insurance. I also caved and bought walking poles in Moissac for €37 (there are cheaper options.) My claimed medical expenses totalled €1380!

Cell phone: €35

I bought a Free Mobile SIM card in Paris with unlimited international phone calls and data. It was €20 a month and €15 for the physical SIM card. Unlocking my phone cost about CAD$50 (but I had already done this). More info on phone plans here.

Wine, Souvenirs, Extras: €100

I didn't buy many souvenirs but there were plenty of chats over wine and snacks that I didn't foresee. I would now consider these social expenses necessary for a fun trip.