@acrah, welcome to the forum.
I walked the Primitivo in July last year, I absolutely loved it. So much so that I hope to walk it again. The trail has a little more tarmac (certainly at the beginning) than I prefer, but that's pretty common on camino. I believe it has significantly less than other caminos.
Whilst I started off injured I didn't find it overly challenging.
Three of us -
@David Tallan, myself and
@dbier all walked it in quick succession and we all posted about it daily - if you look under our names you'll find our individual threads.
Quite a number of people on the trail (50+), but more than enough space that you could walk alone whenever you wished. ( I didn't see that many people on a daily basis, it was an accumulative total from different Albergues etc). My budget was €50 per day, including hotels in Oviedo and Santiago, and apartments on two other occasions. Food was everything from supermarket salad to
really nice (€35?) meals.
I have yet to walk the VP - that's planned for next year.
@caminka just walked the VG, & posted the relevant costs daily. I would imagine that they would be directly relatable to the VP.
Thread 'Caminka on Via Gebenennsis'
https://www.caminodesantiago.me/community/threads/caminka-on-via-gebenennsis.87620/
Personally, assuming similar accommodation styles I'd probably budget €55-60 per day, and hope to come in under. I guess it really depends on how many bars/cafes you stop at, how many cheaper gite de etapes you find, and home made meals you get to make ! It certainly appears that you could do it for less by making smart choices.
I'm taking my tent so hope to come in somewhat less.