Are you in London ?
If not have a look at Centralwings who fly out of E'burgh or Wizz Air and Ryanair who fly out of Pestwick. They should have prices to match.
No i am in Dundee and found the following prices.
Centralwings (EDI to Gdansk) £77.99 - No return flights on 17th
Wizzair (PWK to Gdansk) £81.29 - No return flights on 17th
Ryanair (EDI to Gdansk) £81.02 - £54.19 return 17th
skyscanner.net (London to Gdansk) - flying with Ryanair £37.77
Will keep searching for flights though - Bussing between places might be the best idea when i am in Poland - thanks