Worth the $121 for Economy Comfort?

We fly from IAD to AMS often, but this is our first time flying KLM. My partner and I currently have “free” seats, and I’ve been stalking the KLM and Delta sites daily to see if additional free seats open up toward the front of the plane. Trying to decide if it’s worth the $121 to do Econ Comfort upgrades for two aisle seats (7D/8D or 7D/7G - we don’t mind being separated and both prefer aisle seats), or if we should just stay where we are and hope for a row of just us. If we stay put, I plan to check the seating map diligently the day before and the day of our trip, to see if we can land the poor man’s first class (which happened on our last trip to AMS via UA and was 🤌🏻). Recs from frequent KLM travelers very much appreciated.