Food - Sainsburys, Tesco, Spar, Co-op. Same prices as the rest of the country.
Drink - Cheap alcohol in bars compared to most cities! 1 a pint is a regular promotion. Little or no entry fees into clubs.
Work - There are a fair few opportunities. The university also likes to employ students where it can. However, most opportunities are in summer/Christmas.
Course costs - Books can cost you an extra 50 - 100 per year for most courses. For some courses, diving/boating costs can reach upwards of 3,000 on top of fees.
Transport - To get to Plymouth from most areas of the UK is between 10 - 70 one-way. Once in Plymouth, transport is not needed as everything is within walking distance. However, if you do hop into a taxi, don't expect to ever pay more than 7 (if you're on your own), with a usual fee of 1.40 (with 3 friends).