Conquistador,
It’s a very good question. People should always bear in mind the exit strategy when buying. As a general rule, it’s much easier to buy something than to sell it.
There is a bit of information at the bottom of the page in the costs of buying and owning property in Spain section. Your question makes me realised I need to do a new page on selling property in Spain.
Other than the taxes mentioned in that section, you also need to bear in mind estate agent fees (often around 5% for international sales, less for local sales), lawyers / gestor fees, and banking charges.
Property in general is not the most liquid asset, and less so on the Spanish coast. The easiest properties to sell have the most demand, which means an attractive property in a consolidated area with good access and transport, walking distance to all the amenities. Also, crucially, you need to price to sell if you want to sell fast. So many owners have unrealistic expectations and spend years trying to sell. In my opinion it’s best to drop your price quickly to the market prices where sales take place, and get out fast. That’s on the case in areas where there is demand. If there is no demand, then price loses its effectiveness.
There is also some information in this forum. Check the tag “Selling a property in Spain“.
Do you have any specific questions? And whereabouts in the Valencian Regiona are you thinking of buying