Welcome from Ontario, Canada. The advantage of QAYG is you can quilt the squares without moving a large quilt sandwich. There are many good tutorial on YouTube about it.
Learning to make a quilt sandwich and quilt the whole quilt does have learning curve but you can straight line quilt it.
As for paying so one to quilt it for you, that depends on the size and the quilting pattern you choose. I think Missouri Star Quilt co. is fairly reasonable for machine quilting. Your profile doesn't say where you are located so it is hard to say what the pricing may be like in your area.