It is almost always true that consultants work out cheaper than full-time employees. However, full-time employees can spend time in your business domain for a

It is almost always true that consultants work out cheaper than full-time employees. However, full-time employees can spend time in your business domain for a while and develop a product. The examples given like "wire this up to elastic transcoder" are discrete tasks that someone with very little business domain knowledge can do. So yes if you happen to book an AWS guru consultant to do a discrete task like that one given it makes sense, but there is a lot more to developing products. Also when that AWS transcoder has a problem, it is good to have someone on hand that can fix it and is familiar with the workings.