Shamus, it depends whether you are travelling weekday or weekend. Taxis normally add a supplement on for weekends. Approx cost would be between 38 and 45 euros depending when you travel.You would be better booking an airport transfer with a company it could be cheaper than taxis. Here are some websites you could look at and get a quote from http://www.bravotur.com http://www.algarvetransfersdirect.com http://www.algarve-airport-transfer.com Maybe some other members could provide you with more websites of transfer companies they have used. Cheers Jayjan

Thanks for that info Jayjan will look into that nearer time.

Totally agree with jayjan. You can try a taxi but sometimes they are more expensive. http://www.algarvetransfersdirect.com, or http://www.algarveresorttransfers.com/ are good places to start with. And they also have A 2 B transfers.
You can try also a bus, they are also nice: http://www.eva-bus.com/

Algarve-365.com are VERY good for private transfers.

For the cheapest shuttle service, try Travel Republic.

I can't say too much on here but please -

do searches on this forum and tripadvisor.co.uk before booking
your transfer - it's imperative you are awareof the type of service
they have provided to others.