Prospective investors have been urged to look at the availability of resales on the Spanish market.
Homes Worldwide said that many apartment owners were having difficulty selling their properties quickly, potentially creating bargains for overseas investors.
The website recommended that people carry out research on different areas to see if any bargains were available.
It added that some of the resales could be going at a cheaper price than some new properties.
New-builds were cited as the main factor behind the delay in selling such properties, despite the fact that many were situated in good locations.
The site commented: "It's possible to pick up a real bargain if the vendor is keen to sell quickly."
Citing research by Spanish estate agent Don Piso, Homes Worldwide added that the average time it takes to sell an existing Spanish apartment has increased from 86 days to 120 days since 2005.
Earlier this week, NatWest International highlighted the accessibility of Spain from the UK as one of the main factors behind its popularity as an investment spot.