I am an experienced technology and product leader based in Oakland CA. I have been working in technology innovation in Silicon Valley since the first “dot com boom” in 2000. I combine strong engineering capability, team and organizational leadership skills, and a keen business acumen with a laser-like focus on core product development principles from leading product development methodologies like Agile and the Lean Startup.
I think you are asking the wrong question. The real question is how to validate that customers are even interested in this service at all, and can you deliver it at a sufficient scale to be profitable in the long run. You are not really concerned about profitability in the beginning, so you're mostly pricing just to get the most customers possible to validate your hypothesis. Then, once you have a consistent, albeit small, demand for your service, you can begin to explore ways to scale and make delivery more cost effective.
Also be careful of learnings collected from early adopters. You'll run out of them eventually, and may need to adjust some of your business to serve the mass market. Best to figure out early how these early adopters differ, and how that affects long term profitability, even if you don't leverage that in the service right now.
I think it's important to understand your business goals before jumping into app development. Have you created a Lean Canvas or something like that? Do you know who the customer is and what they want? Has the developer built anything that they can show, even a mock-up or prototype? It's tempting to jump straight to building your idea, but I would caution you to think very carefully about the product/market fit first, doing some customer development, before you build too much. And, if you're on board with that approach, it's a great way to start the conversation with the developer, in terms of their willingness to also validate your assumptions before writing too much code.
The very best talent are attracted to opportunities to do something awesome with other people that they admire and respect. In building a team, it is important to be very careful about your first hires, because it is they (and what you are doing) that will attract the next.
While the recruiting process is sort of a sales process, I disagree with the idea that you will need to "sell" your vision to talent. People judge you (and your organization) by your actions, and that means you need a good vision that practically sells itself. If you are not able to convince people to join you because the opportunity is just so awesome, you may need to think about doing something else.
You will also need to build a company, a team, a culture that makes the best talent want to work there. This means having an actual structure that enables creativity and innovation, working on only focused projects with clear objectives, having an open communication and feedback process.
Money does matter, and you need to compensate great talent fairly. It is better to pay a lot for a few very senior people than an army of remote or junior contributors. This is a fatal mistake I have seen many startups make. In the end you are building a company, and companies are made of people. That should take the lion's share of both your attention and your money.