The TER, or total expense ratio, is a fund's annual cost as a percentage of assets. It is never invoiced: it is quietly subtracted from the unit price, every day, which makes it the easiest expense in a financial lifetime to ignore.
The gap between 0.20% and 1.50% looks trivial. On $100,000 over thirty years at 7%, it is roughly $200,000 of difference in the final balance. The cost is not subtracted from your return: it is subtracted from all the compounding that return would have produced.
It is also the only variable in a portfolio you know with certainty in advance. Future return is an estimate; the fee is a fact.