The cost of operating a roll-up is quite expensive, requiring 10,000 tez to be locked. This amount still belongs to the operator, who can delegate it, but will be slashed if the operator commits an invalid hash. This is much more expensive than originating a smart contract, and it is important to understand the difference between operating a roll-up (originating one) and running a roll-up coordinator. It is understandable to be surprised at the high cost, but it is important to remember that the cost is necessary to ensure the security of the roll-up.