My friend did a job for me and I don't want to pay them.
Is there a reason you don't want to pay them?
I just don't want to.
If you agreed to pay someone for a job or service then you have an obligation to pay the money that you owe them. Whatever price was agreed upon is what is expected to be paid.
Well, I don't think what they did was that much, so I don't think I should have to pay them. I'll find a way around this.
Not paying your friend, or anyone, for the job they did in good faith that you would pay them for their work is horrible and illegal. If they wanted, they could sue you for breach of contract and non-payment. Just pay your friend and don't ruin your relationship with them.