Sure, you can save money building a DIY rod - if you exclude the effort for your own building work.
I've build a few, you can find enough instructions searching the web. A friend of me used to build up Sage blanks.
Another option is to ask a custom rod builder, often they offer a better build quality than the "off the shelf" product.
E.g. https://www.v-stickflyrods.com
or why not ask Paul and a customized HT?
