I definitely know what you mean. This is the story of my craft life! lol
I don't sell anything I make as I only make bows, tutus and hair accessories for one tiny toddler. I pay retail prices for most things thereby over-paying for most things I use.
Would it be cheaper for me to buy her a tutu than make one? Yes. Would it be cheaper to buy her korker bows than make them? Probably yes.
The thing is, I truly enjoy making these things for her. I love seeing her wear them. So I spend the money it takes to make them myself.
However, I have a huge supply of basic craft necessities. Scissors, glue guns, self-healing mats, etc. so I didn't have to buy those. If you need to literally start from scratch, then you might want to ask yourself how much you want to invest in buying supplies.