Hi Steve,
Firstly allow me to wish you all the best in restarting your golfing career. May I ask what you handicap is?
I am currently a member at Font del Llop, I also play at Alenda, which is just around the corner. I also play at most of the other courses in and around Alicante/Murcia regions. As per previous replies, Golf is a lot more expensive these days following the pandemic. There are no real "Memberships" of clubs anymore. They dont want members, they want your money! so its about looking for the best deals available, usually twilight. If your looking to play 3 times a week, then its worth getting a package. Most societies only do once a week, so you may need to be part of few societies. It is true that societies do tend get a better rate , usually around 60-70 euros.
El Plantio is heavily subscribed due to its location to Alicante, it also doesn't fair well in winter
If you want to try and play other courses, my mate Alex Ward (+34 687 84 71 98) does green fees across the whole of Spain and is very knowledgeable of the courses. There are other green fee booking services available. I'm not a salesperson and I am not on a commission. He is just very helpful, so up to you if you want to try him.
Wishing you all the best.