Another cheap/free thing that I find tremendously enjoyable:
Visiting places from my past.
This is very cheap for locations that are within the same city. I merely have to catch public transport and do a bit of walking.
It can be a street, a whole suburb, a train track, an abandoned building, a park, you name it.
I'm not quite sure how to put it in words, but there are aspects of nostalgia, atmosphere and mindfulness to this. I like re-connecting with the sights, sounds, memories of a particular area. Kind of reminiscing and being very present. I'll take a long walk through an area, maybe rest here and there and just take in the scenery. Maybe pull out my laptop and do some work or listen to a podcast. Just basically "be there" in that place. It's very calming and peaceful.
I get that the world is ever-changing and we need to adapt to that, but at the same time, I like to maintain some kind of continuity amidst all the change, and I find that returning to places from the past helps give me that continuity.
Anyway, I don't think change in the world is always instantaneous or arbitrary anyway. It's usually gradual and un-even, with patches of the new mixed in with patches of the old. Like, when smartphones came out, it's not like everyone instantly had an iPhone - people had different phones at different times, and competitors like Samsung came along very early on, so even a change as massive as that was gradual and uneven.
Locations are like this - you see a new building come up one year, then a year goes by and nothing changes, then a building comes down or a part of the road gets renovated, etc. etc. So I see that the character of a location is very slow to change and usually bears some chain of continuity with the past. And most places seem to retain some kind of "essence" that's very very slow to change. I can look at pictures of certain neighbourhoods from when I was a child and see some common elements between now and then.
So I enjoy "keeping in touch" with a place and watching it evolve over time. Somehow it makes me feel more connected to the world and to myself. I think this is the kind of connection people seek when they get out into nature or look up at the stars. For me it's most visceral when it's connected to places from my past, both recent and long ago.
Also I like the freshness of being in a place right now, that I was in years ago. Somehow I feel more alive and awake from having a memory of some phenomena and simultaneously being in direct contact with those phenomena in their present form. Again, perhaps this goes back to the idea of 'mindfulness' and escaping being in one's head by getting back to being in direct contact with the world.