Not to sure the price of rolling tobacco, but cigarette prices are €25-€27 depending on whether you are buying Superking size or Kingsize.
Prices are set by the Greek government, so all places are much the same. Some places will give a bit of a discount or a couple of extra packs depending on how much you are buying.
Look for a brand called Leader, they are €1 for a pack of twenty, €10 for two hundred.

My husband uses hand rolling tabacco never find it that much cheaper in Greece than Spain where it is really cheap but it is less than the UK but take cigarette papers with you as always find these very expensive in Greece if you buy a 5 pack of tabacco you will get 1 pack of papers unless things have changed
pojo

Thanks for fast replies folks.
Gives me a better idea of how much money to take.

You can get a pack called Next, 200 for 8 euros. The box looks a tad like Benson & Hedges.

Not sure where your staying but that was in Lindos btw.

FD

Next have gone up by about 20 cents but Leader are still only 10 euros for 200.All packets have the Government stamp with the price on so they're the same everywhere.