Can you please advice how to get from Pamplona to Saint Jean Pied de Port on a budget? From what I've found so far, the bus is 22e and it looks a bit expensive for 1.5 journey, giving that the same company asks for 24e for the trip from Madrid to Pamplona that is waaay longer. Should I just live with it or there are any cheaper options?
SJPdP is connected to Bayonne by SNCF train usually 4 times daily all year. It costs 10 Euro.
SJPdP is connected to Pamplona by CONDA bus. CONDA schedule and price is listed under ALSA (which has majority stake). Price is 22 Euro. Sked varies on season from none to several daily. The 7 Euro price posted earlier in this thread is not up-to-date information. Its 22 Euros for the bus from Pamplona to SJPdP.
SJPdP is connected to St Palais by Transports64 bus #810. Twice per day. Connect via #811 from Bayonne.
There are not any other public transport options.
Madrid to SJPdP via Bayonne (as well as San Sebastian, Irun, and Hendaye):
ALSA bus (or Renfe train to Irun) from Madrid to San Sebastian.
There are several options to go from San Sebastian to Bayonne.
ALSA (sked varies by season) and PESA (twice daily) operates bus schedule from San Sebastian/Donostia to Bayonne.
There is a CONDA bus that goes from San Sebastian to SJPdP via Bayonne ... its the same price as going via Pamplona. Summer sked only.
Renfe Cercanias goes from San Sebastian to Irun. Every 20 minutes.
Transports64 buses #816 (hourly) and SNCF trains (several daily) go from Gare d'Hendaye (3km from Irun Renfe station) to Bayonne.
You could cross the river in San Sebastian and catch the Metro Donostialdea (every half hour) from Amara to Hendaia (co-located with Gare d'Hendaye.) Its a km from San Sebastian bus station to Amara.
There is not a central bus station in Bayonne. PESA and most #816 buses go to Place de Basques, about a km and across the river from Gare Bayonne. The ALSA site states that their bus goes to TGV Bayonne (which I assume means Gare Bayonne where the TGV trains transit) but Google Earth places the stop on the south side of the river. #811 goes from Gare Bayonne. Some of the #816 buses terminate at Gare Bayonne.
PLM Autocares provides direct bus service from Madrid Avenida de America to Pamplona while ALSA has a transfer at Soria. The only benefit of ALSA is that more of its buses pick up at Madrid Airport T4. So you might want to compare prices.
PLM Autocares lists Pamplona Valcarlos as a stop on their website. I can't get the website to show any bus service actually exists ... it might have done for a short period but doesn't appear to be operating now. There is another old thread on this website that states the bus runs Tuesdays and Fridays. Google Earth shows PLM Autocares bus stop in Valcarlos. The Pamplona bus station does not list any bus company providing service to Valcarlos including PLM Autocares. Essentially, unless someone can find another thread (and I did try Valcarlos Ayuntamiento), PLM Autocares to Valcarlos is out of date information.