This is why I believe true engineering art comes in actually marrying all three: build great quality quickly at reasonable (small) cost!

If you need it to work for at least a month or two (instead of one and done, which some demoware is like). Following a few rules early on will ensure you can keep evolving it — even if it's MVP/demoware/whatever — as long as you know you need to evolve it soon after you build it!