Hey Make…man (first I thought it was Hawaiian. Now I get it). So, as someone who has loved traveling the US in a camper van and mixing in house sits with BLM land, national parks, state parks, places to breathe great air, the rare unnamed big box parking lot… I’m shocked you want to sell your van. It is absolutely the best way to get from sit to sit in the US, and to manage or plan for gaps/off-leash breaks between sits. It’s a great life.
BUT, I’m sure you have reasons for wanting to exit van life. I don’t know your sitch and don’t judge. And respect for you having done van life. But public transportation in the US is [a term THS won’t allow on forums], ummmm…less than adequate. I think of my former home state of Texas. There are good, comfortable, clean busses between some of the major cities. Maybe $100-200 to get from Austin or San Antonio to Houston or Dallas. But then when you get there you will need an Uber (not cheap!) to get to the sit and around town. A van would be cheaper and would have all your stuff in it.
My suggestion: Either keep the camper van to go from sit to sit in the US or go to a country that has legit public transport. We LOVE Mexico. We’re in Mexico City now. We’ve been on a sit here for 2 months. Next week we move to a sit in Puerto Vallarta. Comfortable, safe buses between cities, or airfare for longer trips, are very affordable. Like US$30-40pp from Oaxaca to Mexico City, for example. Or our flight to PV was about $100pp after paying for luggage. To ride the metro (bus or underground train) pretty much anywhere in Mexico city costs about $0.30. Ubers are maybe $4-5 around town. The most I’ve paid for an Uber, when it was pouring rain and prices elevated, was $16. (Tacos are $1-2!!). We walk for groceries maybe half mile. We walk for tacos maybe 30 feet. Or there are city bikes ($30 for an annual subscription all you want to ride) that are awesome.
I will never poop on Colorado. I’ve spent a lot of time there in my life and love the state as a second home. I’ve done several sits there, and my son lives there. You will find a few shuttles from Denver to ski resorts in season, but otherwise public transport is American-style. Which means it barely exists. I always had a car or van.
Some US cities will have bus service that will get you around. But the US (let me waive my native flag here) just isn’t set up for that to be easy. Except in major metro areas. Where everything (food) is expensive. I honestly can’t imagine how we could have done sits (mid-late 2023 in 7 western states) without the camper van. And mixing in house sits was a great way to get free showers & laundry, cook in a real kitchen and have canine/feline companionship. It also gave us so much freedom to NOT house sit some of the time.
Also, I have found rome2Rio to be entirely useless and inaccurate. Google maps is pretty good internationally. Never heard of Wanderu.
Best of luck. Love your journey.