Here in MN I get pretty nice cedar from Lamperts. They are more old school lumber yard, not comparable to HD or others like it.
I buy 1 x 3 and 1x 4 for nearly the same price as the big box.
1 x 4 cedar, rough on one side = $5.19 each. Mostly knot free as I sort for them. Some small knots that affect nothing (the smaller ones actually look nice when the paddle is finished). I have never had a paddle break and I like to make them thinner and lighter.
I saw them in 1 1/2 strips and laminte them, sometimes using repurposed redwood I have.
There are also nice 2 x 4 there that would work if one does not want to laminate blanks.
2 x 4 x 8 = $11.39 each.