You can't put a price on it.
Ask someone "What is the most valuable thing you have?" and depending on their stage of life the likely responses will be; "My house", "My car", "My phone". Of course all of these answers are totally valid ... if you are talking about monetary value.
I would argue that the most valuable, precious thing we are likely to have in our lifetimes, is true friendship. Not just someone you hang out with occasionally or a facebook friend ... but an absolute "bestie". You know, that special person who maybe you don't see for months on end, but when you do it's like you haven't been apart ... everything is just normal, conversation flows ... everything just ... is.
I was lucky enough recently to be able to share some time with my longest suffering "bestie" (Bill) and even luckier that my best bestie (my wife) could do without me for a week so my mate and I could indulge a little wanderlust and road trip from Melbourne to Sydney (via the coast).
We had a start date and an end date, everything else was freeform ... we also hadn't spent more than two days together in over 30 years! Bill's main aim of the trip was to have a look around and get a feel for the area. Mine was similar ... but with an obvious leaning toward the photographic.
We had 6 days sharing accommodation and the interior of a Hyundai i20 (who later became affectionately known as Daisy). The most difficult part of the whole trip was finding somewhere to stay that had seperate bedrooms and didn't require a weeks's wages. We are very good friends ... but we both agreed we needed at least some individual space. Cabin parks became our go-to, with most being very comfortable (if usually a little distance from our intended destination). A couple of parks actually provided the bonus of being in very picturesque settings which we would not have found otherwise. (Broulee)
We survived our time together ... in fact it was a breeze ... a pleasure (although flying with a full-on head cold is not recommended ... but that had nothing to do with Bill). We saw some more of our beautiful country, met some lovely people and reinforced what we already knew ... that true friendship is just the BEST.