I'll bet the official app would be better than any of the ones you've linked there, all dem high ratings. I'll guess they're all just web wrappers? Ergo they're not proper apps. They just exist to get someone some easy ad money.
Price isn't the RTs problem, it's the lack of apps. If it had a Store that was even on a level of Windows Phone never mind iOS it'd have a decent chance of making a dent but people want good tablet apps, something RT is still bereft of. Until that changes it isn't a serious contender. At least with proper W8 tablets you're getting a full Windows experience.