Ask HN: Is it normal to pay to a digital marketing agency as a pre-rev?

Hi all,

I have a B2B SaaS startup, trying to personalize UX, got +4 LOIs so far.

A digital marketing agency came out to me and said "we will help you to get $10k/mo. as pricing, you pay $500 now and $2000 after you get $10k/mo."

Does this makes sense to you?