Neither can I, and I have 9 Commander decks. Very rarely do I spend more than a few dollars on a single card, and even then it's been maybe $15 at most.

Those cards that are that expensive are good (provided they aren't just special printings of cards that are otherwise less than a dollar), but they're absolutely not necessary in casual formats. Most of the time, there's a <$1 card serves the same purpose. There's even a format called Pauper where only commons are allowed.

Standard is where it gets excessively overpriced, and it's a big reason for its decline in players over the past few years. If you want to play it, play Arena, which is F2P.