The first rod I built (12-14 year ago)I was going to use the cheapest blank I could find for practice, but the rod builder that got me started suggested to build the rod I wanted with a mid price blank. I wanted an ultra light jig rod for panfish, and I built that rod with a mid priced blank. 10+ years later that is still my goto rod when jigging for panfish.
You can buy a 60-70 buck blank, add some components and have a nice usable rod for many years!
Not saying that starting with budget blanks is wrong, I'm just giving another option. An when it comes to rod building the options become endless!
And as suggest before Mudhole has many video's to help and free ship over $99.
Good luck and if you have questions there are some very talented builders in the rod building forums!