Actually I think they'll be considerably higher than that considering what I anticipate the value of Bitcoin to be at that time. Mining fees will need to be reduced considerably for Bitcoin processing to remain "cheaper than alternatives" when Bitcoin goes north of US$10K, or the per-coin transaction fee will be 80 cents. Even for smallish purchases there are usually at least 3-4 txid's involved, so is a "usual" transaction fee of $2.40 or $3.20 per transaction entirely reasonable for processing each and every one of your daily purchases? Bearing in mind that today credit card companies are doing it for a nickel or so plus 1% of the transaction amount?
So save that dust; if they do reduce transaction fees in the future, it may become spendable again.