This may be hard to hear, but it is true that people don't always realize the cost of materials and your labor in making your quilts.  This video details the costs for a Queen size quilt, and the total surprised me.  If you are curious, you might want to watch this video on You Tube.    Click Here

We often joke in our Zoom sessions that if you have 12 quilters, you will get at least 13 opinions!  So video's like this are helpful for us to hear the reasons someone likes certain marking methods when quilting.  There are many other options, but here is one experts viewpoint with good reasons for her choices.
I happen to use both of these tools, but also have other methods I often use.  By the way, not only can these be used for Free Motion Quilting, but also marking to match up seams when piecing.  I just did some Tumbler Blocks with slanted side seams, and a little mark in the middle helped me line of the seams perfectly.