Depends on your Power Bucks total. If you have little then placing one bet per product increases chances of wins than placing all bets on one product.
Going "all in" becomes progressively wasteful. For example, it is unlikely but possible to win all 3 products (1 of each) in a week, but you can never win 3 prizes of 1 product in a week.
You can also be tactical, bid on items with with fewest entries wait til end of Friday and bid on only those with low entries. That would give most chance of winning.