What? It's 1 DEC per 30 days not $1. That means your $1 will be around 1800 DEC or 1800 months or 150 years. I feel like you're a botter with 1,000,000 account for you to be bothered with a 1 DEC per card listing. How many cards are you listing on the market and how many of them are rented out? I'm really bothered and curious.
There's a really easy solution if you're really concerned about the DEC price fee. It's 1 DEC per card so if you're currently renting 800 level 1 cards and don't want to spend 800 DEC per month/per listing, just combine the cards and rent it for a higher price. You not only spend less than 800 DEC but also get more for your money.