FWIW luvmydogs, we are just extended timers right now and have been for many years. At this juncture we have not purchased any passes other than a Washington Pass that saved us considerably last Sept, and the America the Beautiful Pass (we are in our fifties and Canadian). FWIW, as we start FTing, we don't intend to purchase any passes until we are maybe in a situation where it might save us more than the cost of a couple of nights at that juncture (ie; Passport America). We will for sure join Escapees as we feel we want to support that overall membership for how much it's done for us and other RVers over the years anyway and at less than $40 = why not? We likely will try to use at least one of their parks, and the Days End Directory for us will likely be most useful.
We Boondock/dry camp extensively by choice, and our first go to resource is www.freecampsites.net. When we eventually get to New Mexico we for sure will plan around being able to take the maximum advantage we can of the State pass at $225 to enjoy that state.
When we drove from southern Alberta up through to Yukon, NWT and Alaska, coming back down through BC towards just south of Calgary, we found plenty of options for boon docking and some $10/night areas watching Stellar Seals & Otters tossing salmon at 2am and 3am in the morning through our windscreen. As well easy walks from these for hubby to get his salmon fishing (think snagging here!) and bear fix!
Everyone has a different way of RVing, comfort levels and to each their own, but this is what works for us being quite free spirits in our travels, and hopefully something here might be of use to you.
We decided against joining any of the more expensive bigger memberships until we are actually out there FT, due to tying ourselves to just those parks which we might not like to use = think having an annual skiing pass most years living an hour from Banff forced us to ski more than we might have to get our monies worth, so lesson learned on buying term memberships/passes. Also have read of so very many folks that ordered several to start with and eventually 3 or 4 years later are down to maybe one or two.
Enjoy your trip and Happy Travels.