The islands' currency is the Seychelles rupee SCR. ATM machines usually have the best conversion rates, however, airports and banks also conveniently exchange money.
Trading in foreign currency, long illegal, was legalized in November 2008, and the currency freely floated. This has also wiped out the previously wide-spread black market, which offered up to twice the official rate. The £ buys around 21-22 Rupees on Jan 2012.
shopping
The best place for shopping is Victoria, the capital, and more specifically the market at the city centre, Seychelles Buy and Sell (http://www.seybay.com/). There are also a few outlets on the island, Praslin, but few shopping areas on the other islands. Larger hotels have boutiques but shopping in Seychelles is not one of the major attractions.
While visiting, be sure to buy the classic and traditional Seychelles souvenir, the coco-de-mer, or the 'nut of the sea,' a nut from trees native to the islands in the Seychelles - but this requires an export licence. Other locally made souvenirs, although not as unique, can be purchased like sea shell and pearl jewellery, textiles and straw hats, in addition to needlework & crochet, paintings by local artists and woodwork.
tipping
Most service providers already include a service charge of 5% - 10%. Tipping is not obligatory in the Seychelles, however, any extra change is greatly appreciated.