A Eurail pass is often not great if you’re mostly travelling in Spain. As you’ve found, most Spanish trains need reservations - and these can be pricey (and sometimes hard to buy).

In other countries (UK, Germany, Belgium, NL, Germany, Austria, Switzerland and more) you don’t need reservations and the pass is great value.

There’s a good guide to reservation costs here:

https://www.seat61.com/interrail-and-eurail-reservations.htm

Have you priced out the cost of individual tickets for your route? Most Spanish trains can be bought on www.trainline.com or www.raileurope.com . These aren't the absolute best websites, because they charge booking fees, but they do make it easy to check prices.

Spain releases its tickets quite late, so if you don’t see any results for your search, check dates in the next few weeks to give you an idea.

Where did you get the price 700 USD?

A 4 day senior Eurail Spain Pass costs 199 USD. I guess that you missed to delete the preselected youth pass and got the price for several passes for 700 USD.

As a rough guide, a ticket for Barcelona-Valencia can be as little as €18/37 in second/ first class if you buy in advance, maybe €60/ 120 if you buy it on the day (if there’s seats available).

Here’s a great guide to travel in Spain, including common journeys and how/ where to buy tickets - if you decide not to get a pass.

https://www.seat61.com/train-travel-in-spain.htm#How_to_buy_train_tickets_for_Spain

You could also consider the RENFE railpass - details on that same page. It’s a similar price, even with no senior discount, and there are no reservation fees on that one. But I don’t know much about this pass.

I think @KButterly was looking for First Class, so they would be $254 each. But yes, there's no way to make it add up to $700.

The price for a 4 journey RENFE pass would be about $288 each, with no reservation costs, so probably cheaper than a Eurail Spain pass + reservations. And a lot easier to book the trains.

But I think if you can book in advance, regular tickets will add up to much less than $288.

Out of interest, I just checked prices for your four journeys.

I could book those four trains for tomorrow, for about $240 per person total, in first class. Looking further out - about a month - it’s about half that.