If your looking to make sales you need to do one of two things.

#1 Make and app the fills a nich. Something that people will want but no other apps like it are available.

#2 Make the app a better quality product than competing apps.

Most definitely! The microISV world is full of me-too software. Even if yours is the best, why enter an already crowded marketplace?

Just to toss my two cents in ... I am a developer but looked at obj c and while I could learn it and android and blackberry API, I stumbled upon titanium appcelerator a month ago and have been impressed a lot.

It's neat from a developer point of view to write once, in javascript, and run on multiple phone platforms. In my spare time I have been messing around with their Apis and sample code.

Mighht be worth a look. There are other products too filling this niche.