Not sure why someone down-voted you, but as someone who has been hired to build lots of iOS apps, it sounds like what you're saying is NOT that it should be cheaper to build iOS apps than it is, but that being able to explain how the developer is delivering commensurate value will let a "business person" justify that high price.

Exactly. My fault for not being clear myself.

I don't disagree with you but I think ROI is a business owners case to make. You know your projections and it is up to you to take what I say it cost to fairly compensate me and see if it matches with your expected ROI, if it does not, we can negotiate, if the numbers are not there, then they are not there. But I don't think it is on me to prove out your ROI. Chances are you already know this number, before you even start soliciting bids. Now if I come to you with the idea, sure I would expect to have to prove the case as to how it will benefit your company.

Agreed. You can help the business person pay more for development if you can help them maximize revenue or lower marketing costs (or some other outside expense)

If you think of development as using technology to scale down cost or scale up revenues there is plenty you can add as a developer to the ROI discussion.

agreed. ROI calculation is not for the developer but for business owner. Business owner should start with a budget, an idea of what he would like, and then the developer should tell what he can deliver for that budget.

And yes, building iOS apps is still hard and time consuming compared to webapps, business owners should know that:)

An estimate for Twitterific is 200K (provided by the authors of the app). Still willing to venture in an iOS app?

I have a really tough time editing on android device so I added this rather than editing. It is worth pointing out that I used "i" for illustrative purposes. I read HN for the technical knowledge and comment on business posts (my area of relative strength).