Frugal is the word I prefer. But fees and commish add up. Like walking away from the blackjack table having lost you stake and the dealer has a hundred bucks in tips.
If your broker does not charge commissions for trading certain ETFs, look at the spread and you will see where the commission is applied. It is a common trick to offer "free ETFs" where the spread is wider and you end up paying the same amount per trade.
I strongly prefer XSP. I write short term contacts. The bid-ask spread isn't as bad as it seems, the MM will hit the mid +- a penny in calm markets. Cash settled and 1256 and free of index fees up to 9 contacts. SPX is better but you should be trading when you have 50-100K in your account or the sizing is going to bite you. At $0.50 commissions per trade, 10 spy contracts is $5 so I'm more than willing to accept $0.50+0.50 index fees to get 10X sizing in SPX Liquidity gets better every day
If you look at BID/ASK you seem to be right but look at all markets when compared to ES Futures. Cells and annotations are slightly off because it is a quick collage from different websites. I apologize for the brain fart. ES is supposed to be the underlying for all markets. SPX and XSP are following closely as expected, but look at those 2 points of difference in the SPY market. That is where they get the cash, it makes sense, they are not going to run an ETF for free.