Interesting thread! I have never used an estate agent to buy property in Spain. I did know the area and speak Spanish, maybe different for someone from the UK and new to the market. I found that most sellers not using an agent were sometimes asking more than a similar property with an agent. Sellers can be just as “greedy” as an agent.
What I have never been able to do is sell a property privately 🙁 even in the boom years. I once paid 10% commission to an agent in Banus, and, was happy to do so as they sold it quickly and for a top price. Sold two through VIVA and paid around 7% and was content with that too. Despite whinges about commission charges I think sellers would be happy to pay really high charges just to shift the property at the present time.
To sell privately one is at the mercy of dodgy websites, some free but others charge around £50 to £99 just to advertise. The most interest you will get is from scammers who claim to want to buy the property without seeing it!
Personally, I do not know of any property selling in my area, it is completely dead. Think I read that investment into Spain last year fell by 91% which I think says it all.