The majority of watches here are poor quality Chinese fakes ,which is where the majority of fake watches are made.The ones that Ramos sells are at the lower end of that scale.Fethiye watch centre do higher quality but you are not going to get anything decent or even close to the gen article for £100.
Best thing is for your friend to do a bit research on the Internet ,find a trusted dealer and expect to pay around £350 for a good quality submariner.
Don't believe anyone in Turkey that tells you they are Swiss movements,they are not.More likely to be Chinese 21j,hand wind seagull,Japanese miyota or sellita ,all good but not Swiss.