Last August I bought the Olympus OM-D with the 12-50mm lens. Later I got the Oly 45mm. I use this gear for street photos (my hobby) and for family pictures. For a while I considered buying the Panny 20mm but that changed when Olympus released their 17mm f/1.8. Now I am also considering the Panny 25mm... My first question: is this a symptom of GAS (gear acquisition syndrome)? If not, which lens would you buy (taking into account I am just a grad student with no $$$)?