Hosting your site will be an on-going cost. TYPO3 does not take well to bargain-basement hosting, but it is perfectly feasible to use it in a shared hosting situation, such as that we provide as a commercial product, provided your site is neither too large, nor too busy.

Beyond this, TYPO3 is very scalable. If your needs are very ambitious, you will need to budget for a suitable level of infrastructure to support them.