How the cost will increase in software engineering?

When you say that the cost of software will increase. how the cost will increase. i mean for making software we need just computer. my question is that every one who knows software engineering can make software if he/she has computer or they should require anything else which is costly?

Software development requires use of system but there is alot of other paper work, meetings, stakeholders involvement, hiring experts etc. Here software means complex and large softwares. Software development of such softwares involves multiple teams; requirement engineering team, designers, programmers etc. They communicate and work together to deliver a software to customer.  Software team needs to dig requirements from domain, from customer even from organization. A little mistake not only requires alot of work to do again but also cost in terms of resource allocation, money, time etc.