Typical!....which is why I feel agents should be more strictly regulated, including how much commission they can charge. Clearly what has happened in this case (as with many others) is that the agents as usual ask the seller what "net" price they are looking for, then just whack on whatever commission they feel like before marketing the property. The result is disillusioned buyers like T'Pau, whose confidence in the Spanish property market is shattered before even getting a foot in the door.
The debate will always go on as to who actually pays the commission (buyer or seller), but as a seller, I always try to insist that all agents listing my property do so at the same price. So when they ask me what net price I'm looking for, instead, I tell them what price I want it marketed at, then ask what commission they want if they make the sale. This way I can ensure that all agents offering my property do so at a price I believe will be achievable (no point advertising it at an unrealistic price in the greedy hope that someone may pay it, unless of course you're not really that serious about seling), plus I can decide whether the agents that want higher commission than others are able to offer me anything extra for it - such as a greater chance of achieving a sale, due to better marketing or sales techniques.
Basically, since the seller chooses which agents the property is listed with, I feel the seller should also be the one choosing how much commission is payable. The buyer is of course free to "shop around", but as I started by saying, such huge variations in advertised prices only causes a negative effect on the market in general.
My sympathy to T'Pau, it's a rotten situation to find yourself in. I would try talking to your agent about this, but don't hold out too much hope of getting anywhere. The important thing is to remember that you chose this property because it ticked all the right boxes for you, and until you started looking around after agreeing to buy it (why do we always do that?) were presumably happy with the price. So as long as it still ticks those boxes, why not go ahead with it anyway? Contrary to what some people would have you believe, the Spanish property market in the mid to long term is as safe an investment as ever, and it will appreciate over time anyway, so just because you feel now that you could have got it cheaper, doesn't mean you 're not still geting a good investment for the future.
Good luck with your purchase!