Do your own homework as anillos says. No one call tell you which is better without pricing both and to do that you need to provide a specific itinerary.
In general, a pass saves you money if you use it a lot and doesn't if you don't use it a lot. What a pass also does however is tend to make you want to 'get your moneysworth' out of it. That in turn tends to push you to move more.
That in turn leads to the question of what your travel philosophy is. Most here will agree that in travel, less is more. The less you move the more you see. The common phrase used by first time travellers is to want to see 'as much as possible'. They then equate the word 'much' with the word 'many'. They are not synonymous. The way to see as much as possible is to spend time IN a place rather than between places.
If you adopt that philosophy then moving a lot is out of the question. So for example, in 3 months you might plan to visit perhaps a dozen places. Comparing 11 tickets between them to a pass might work out cheaper to buy as you go. If however you plan to visit "24 places in total" in 3 months well, you're into quantity not quality and a pass might work out cheaper.
Besides quantity vs. quality, a pass also has another downside. It locks you in. Sure you can travel on any day with one but what if you decide to travel outside its area of use? Or suppose you decide to stay in a place and not use it at all for a month? Oops, here comes 'get my moneysworth' raising it's ugly head again.
Suppose a month into your pass, you are in Rome sitting on the Spanish Steps. You meet someone who mentions that he is planning to take his VW camper across the Med and then drive it across the Sahara and ultimately to S. Africa. He also mentions he is leaving in 2 days to do this and is looking for some like minded people to join him and share expenses. What do you do? (This is an actual example of an opportunity that happened to me personally. I had no pass, no plans and away we went to Africa.)
Throw away your $2k pass and join him or say 'Oh we can't do that, we have a pass to use and a reservation for a hostel in Florence next week.' I can tell you that most people would not be able to see beyond the blinders the pass puts on their eyes.
Here's the thing 421. You guys seem to want to embark on an adventure. That's no different than thousands of others plan to do every year. We see countless numbers of them here on the TT, there is nothing unique about your plan.
However, the vast majority in fact simply go on a tour, not an adventure. An adventure requires two things by definition, the unknown and risk. So by definition you CANNOT PLAN an adventure. You go to A and see what happens. You stay till you are ready to leave and then decide where to go next. You have to wing it.
Planning a list of countries to visit whether you do it with a travel agent or on your own, is simply planning a tour. If you want an adventure give that some thought. That to me is the difference between a tourist and a traveller.
Tourists move too quickly to get to know where they've been vs. travellers who don't decide where they are going till they get up that morning. I once went to an island expecting to stay a week or so, I stayed for 7 years. It wasn't that I decided to stay, I just didn't get around to deciding to leave till 7 years later.
