Welcome to Business!

You are asking a lot of hard questions.

The first part, estimating income, can be done with market research and experience. It is not free and tricky to get right. It requires experience, and even big companies get this wrong.

The second part, budgeting, is emotionally difficult to balance your ideal world against the harsh realities of the real world. It is an exercise in discovering what is really important, and discovering the actual costs (not your guesses) to get it to the quality you want. Then refining what you want down to what you can afford.

Quote:So, just plucking a figure out of the air, let's be generous and say I could sell 9,000 copies at 2.99 (I'm working in GBP rather than USD, if that makes a difference) - by the time Apple takes their cut, that gives me a total budget of about 18,000. But how do I know if that's utterly ridiculously high? Especially given that this is my first forray into this market, and I have no idea if 9,000 is a realistic number.

That is a big question. There are many university degrees that focus on the question, and major companies hire lots of MBA graduates, economics experts, and statistics experts to try to get answers to this.

On your question of income, you will need to look at how similar products fare in similar markets. You will need to consider that you are the newcomer against any incumbents, that you have no existing brand recognition, and you will need to figure out how your marketing will affect it. This is the biggest part of demand planning, which is just one part of getting an accurate sales forecast.

That estimate requires market research, plus experience. It is easy to get wrong. Without accuracy, your budget is just a number picked from the ether, as you did above.

Quote:But anyway, by the time you've got all that to spend money on, suddenly 18,000 seems utterly ridiculously LOW... Is it better to spend more on just one or two areas and then attempt to find volunteers to do the others? Or better to spread the money out evenly between the different stages? Or something else I haven't thought of?

Budgeting is hard.

There is no point on spending money on the wrong things. If you spend ANY money, make absolutely certain you are spending it on the most important features.

Make a list of every feature and component. Prioritize them. If you only had the top feature, would you have your product? If not, break your parts out differently and re-prioritize. Then repeat for the second most critical feature, third most critical, etc. Usually the very first items are minimalist bare-bones prototypes and concepts; you probably couldn't sell them, but at least they represent your finished product. Figure out the cost of each item on your list and subtract it from your money pool. Be very careful that you provide realistic costs --- it is generally more than you initially think. When you run out of money, stop.

That's all the features you can afford. Everything else gets cut.

Then you need to repeat the demand planning against just those features, and re-compute the sales estimate based on the new, smaller product. Then you need to cut again to get down to the new budget, then get a sales estimate, then budget, etc. Repeat until stable.

If you don't like the results, you need to re-prioritize again, get more funding, or find ways to reduce costs. Eventually you will either discover that your business plan was not viable, or that you can possibly break even.

If you discover partway through that you are spending too much, the bottom item gets cut. Repeat the steps above, and cut the least valuable. If you make the happy discovery that you have additional resources, add the item just past the end of the list.