Unfortunately, Ryanair have recently reduced their daily service to Madrid from Faro to 4 days a week and so the option of flying low cost Faro - Madrid and then low - cost Madrid - Malaga with Spanair is not an option on 14th July 2007.
Your best bet will be therefore to get the 08:20 DAMAS/EVA bus from Faro to Seville arriving Seville Plaza das Armas at 13:00.
Form my research there appears to be a departure from Seville at 16:00 for Marbella. Transit time 3:30 mins - so arriving Marbella 19:30. The operator is AUTOBÚS DE LOS AMARILLOS. They do not appear to have a website.
My reference to this is here:
www.ctsa-portillo.com/ima/pdf/marbella.pdf
This appears to be the best option.
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