Those numbers aren't quite right. Keys cost $1, and the lowest-end rewards from blueprints cost 100 credits (which is $1). So, if you want the cheap stuff, you'll get it at the same price, and get it without question - no opening dozens of crates to get the one item you want. The highest price I've seen for anything in the blueprints so far is 1600 credits - and I'm quite certain that the chance of getting those items from a crate before was less than 1/16.So Rocket League has made a change to their MTX, and for the worse.
Old way: You would get crates (lootbox) dropped in game. You could open it with a key that you bought for $5 (and later with a decryptor that you could earn in game), and you'd get a random item from within. You could get duplicates of items.
New way: You receive blueprints for items. You spend credits to craft said item. You can earn a teeny tiny amount of credits by playing (battle pass), or you can purchase.
The problem is, the costs of the builds for the blueprints are insane. They range anywhere from $5 to $25. And of course they set the credit costs of the items to be in between the purchase amounts of the credits (i.e. a car can cost 1200 to craft, but you can only purchase credits at 500, 1100, 3000, and 6500).
People are of course blaming the fact that Psyonix was purchased by Epic for the prices.
Despite the furor, nothing much has actually changed. Without any keys/credits, I couldn't open the crates before, I can't craft the blueprints now. But now, I know what's sitting there, and I can make a far, FAR more informed decision on where to throw my money. The upshot is that the crafting cost is going to have a deflationary impact on trading prices (people generally have an idea of how much an item is worth). The low-end common (Uncommon and Rare) crap that nobody wants will become worthless, or nearly so, on the trade market. But they were already not worth much (.05 keys was a price I saw for one).
Unless you think you need to open every crate and craft every recipe, the game likely costs you less now than it did before - and if you never invested money to get the shiny rares, then nothing has actually changed for you.