Here's some options. The prices are only a rough approximation, as most hotels nowadays use dynamical pricing.
Hostel/affordable:
Bed & Breakfast Tuure (from approx. 50e, 0.4 km from city centre)
Hostel and Museum Ship s/s Bore (from approx. 50e, 2.6 km from city centre)
Omena Hotels:
Omena Hotel Turku Humalistonkatu (from approx. 70e, 0.45 km from city centre)
Omena Hotel Turku Kauppiaskatu (from approx. 70e 0.2 km from city centre)
Hotel:
Hotel Helmi (from approx. 100e, 0.5 km from city centre)
Scandic Hotels:
Scandic Plaza Turku (from approx. 100e, 0.3 km from city centre)
Scandic Julia (from approx. 130e, 0.3 km from city centre)
Scandic Hamburger Bors (from approx. 150e, city centre)
Sokos Hotels:
Original Sokos Hotel Kupittaa (from approx. 140e, 1.6 km from city centre)
Solo Sokos Hotel Turku Seurahuone (from approx. 140e, 0.5 km from city centre)
Original Sokos Hotel Wiklund (from approx. 130e, in city centre)
Centro Hotel Turku (from approx. 110e, 0.3 km from city centre)
Holiday Club Turku Caribia (from approx. 100e, 1.6 km from city centre)
Hotel Kakola (from approx. 110e, 1.4 km from city centre)
Radisson Blu Marina Palace (from approx. 100e, 0.7 km from city centre)