1 cent per write to a database is insanely expensive, and no, you can't pay that much for DynamoDB. DynamoDB is free tier for 10 writes/read per second.
If you go with AWS's most expensive option for access (DynamoDB on-demand, infrequent access), the pricing is $1.56 per million write request units. That's 0.000156 cents per write. That doesn't include data storage, but that ranges between 10 and 25 cents per month, per GB.
However, transaction "gas" fees with some chains (Polygon, Solana) are less than 1 cent and you probably know that.
You can pay as much with DynamoDB if you don't optimise anything (and reads are free with the chains, still costly with DynamoDB). Of course, you can say that AWS is overpriced too... maybe that's just inflation going on.