I wouldn’t think it that way. The first thing that you should consider is what you will manage to do by using an ERP system. In other words, how can an ERP system help and what it can offer.
To answer your question, it costs money and it takes time and effort (which also cost!) so it’s not easy to implement especially by an organisation that it’s either very big or by an organisation with limited resources. There are benefits however so it’s better to try to approach by using a cost benefit analysis.