[Terretta]

As owner of > 500 purchased apps on Mac App Store and iOS App Store, and careful observation of buying trends at various price points, I'd say $4.99 is the impulse ceiling.

For iOS apps I am familiar with and use regularly, I have paid as much as $49.99; Mac apps, as much as $299.

This app, to me, in its current incarnation and marketing, looks like $4.99 "launch price" and $9.99 tops once it's finished (it doesn't look finished). There are notably (sorry) better editors for less money.

    Writeroom $9.99
    iA Writer $8.99 (iOS $0.99)
    Byword $9.99 (iOS $2.99)
    OmmWriter Dāna II $4.99

Perspective:

    Pages $19.99

Given the competition and its marketing, I'd recommend undercutting the other guys by as much as 1/2, and discounting your launch pricing further.

// Disclaimer: utterly speculative opinion, YM will V

EDIT: While researching these, I discovered "Marked", and saw it offers GitHub technical markdown preview. I purchased it for $3.99, because I hadn't spent money on coffee today.

[gregd]

I would have to agree with @Terretta. A launch price is probably your best bet while your user base grows, praises and criticisms flow in (along with reviews), a few updates to the program happen and you finally settle on a price that can sustain further development and feed your family.

All of this is moot if $14.99 is indeed your launch price.