Kolbudy sits roughly 15 km south of central Gdańsk, putting it inside the PKM (Pomeranian Metropolitan Railway) commuter belt but well outside the premium pricing of the Old Town and Sopot seafront. Accommodation here tends to be guesthouses, agrotourism farms, and small pensions rather than international chains, which is the single biggest budget lever for a Tricity visit. Combine that base with a weekly transit ticket and most major sights are reachable in under 30 minutes without a rental car.
The East Pomeranian Lake District setting means many of the day's 'attractions' are free: Radunia lake edges, forest walking and cycling trails, and small village markets. Paid anchors (museums in Gdańsk, Malbork Castle, Sopot pier) are best treated as 2–3 day-trip splurges rather than the focus, which is how the cheapest itineraries stay on track.