Answer:
Fixed costs:Monthly web hosting feeMonthly Domain costsMonthly recurring fee for website creator (e.g. Wordpress, Weebly)Monthly energy costs
Variable Costs:Media creation (videomaking, photography, graphics etc.)Content creation if you use a content writerSEO analysis (if you outsource an analyst)
Explanation:
Swift is making a satirical statement of several concepts.
One would be on the objectifying of humans (computed cost for babies...)
Two would be the idea of how they can easily spare the children by merely reducing them to costs, especially from poor parents.