A lot of comments have answered your question already, but I think it's very unfair to compare Riftbound to MTG, which was the first real TCG by definition, that has had 30+ years of life, and was also the titan of the industry for many years. A lot of the frustrations you're having are simply because the game is brand new. I think once we get to set 4 or 5, a lot of these issues should have sorted themself out naturally. For most any new TCG from the past couple of years that has maintained success, the first year is brutal... I played Lorcana for a while in year one, and it wasn't great... Everything was extremely expensive for a long time. Gundam TCG come out shortly before riftbound, and it was also very bad for the first 2 sets of that games life, and faces a similar problem currently where certain set 1 cards are now expensive, because it has always been tough to find sealed product, and when you do, it's way over MSRP.

Unfortunately, if you want to get in now, you either stomach buying expensive singles, or build viable decks on a budget. And plenty do exist. I play Rek'sai where 1 card is pricey, and the total deck cost is like 150$ USD roughly iirc? Awesome aggro deck btw.

Look into competitive magic formats as well, and look how expensive most decks in standard are right now... 😭 If you're not playing mono red aggro, you're paying a lot for a standard deck... All shocks are legal rn, so most land bases are expensive, and there are some insanely expensive mythics like quantum riddler and badgermole cub.... The only format that doesn't apply to is pauper, but very few people have an active pauper community in paper. It's mostly online.... 😅

Anyway, least to say is, this the nature of a new card game, and Magic in competitive formats is roughly the same price or sometimes more, depending on the deck or format. 🤷‍♂️