Perhaps falsely, but I was under the impression that once an app is purchased by me thru iTunes...I can 'purchase' it again at no additional cost (i.e. iTunes records transaction completed). Repurchase (for lack of better words) transaction would complete at $0.00. Not true?
That is true, if you're logged in to iTunes under the original purchasing account and select to purchase a previously bought app, you will get a popup just before download saying you already own it do you want to redownload...Just be sure it's the same exact app, ie not iPhone version when original purchase was HD version etc...