Maybe Alberta ducks are stupid, but my brother and I use some cheap calls and we do very well all the time. Buck Gardner calls, maybe not the $12 one, but you don't need to spend more than $40 and if you wait for a sale even better. ...the only problem with the super cheap one is that they only spend about 10 seconds tuning them. If you know how to tune them yourself then give them a try. Get a couple so if one freezes up you can stick it down the front of your shirt to melt and switch to the other. Stick to the basics. 3 or 4 or 5 quacks with the correct cadence. Work on being soft or raspy, calm or excited...or desperate as a last resort. And soft happy calm feeding noises if they are circling straight over head. Please don't waste your time with crazy hail calls or super fast feeding calls. You ever hear a duck or group of ducks do that? Go listen to some ducks sometime and just observe, then try to have a conversation with one, watch how they communicate with other ducks flying around.
Otherwise, ducks come in fast. I would say your decoy spread is more important to make them comfortable landing. And when they look like they are coming in just shut up and let them come in. In fact, if their eyes are facing your direction you probably should be quiet...you know many ducks that sit up in the bushes making all sorts of noise while their friends are out in the water? If they look like they are going to land far away from you then give them a call, get more desperate sounding as they approach the water. Same if they veer off, give them a little call, if they keeping going get more desperate. ...once they land elsewhere, or fly away, you can't really do any harm. About the worst thing that can happen is if they choose to land a little distance away from you because they are far better looking than your decoys and sound much better than you ever will. ...but when you fool the next group to come to you instead of them, especially after they circle and change directions a few times then you will know you have figured out calling.
I love ducks, but I wouldn't appreciate them as much if I didn't hunt them. ...ah that whistle a landing ducks wings make before first light. Gives you chills.