It is valuable to consider the you-centric position on why you need to charge a lot, but also keep in mind why your client gets more valuable out of you, in such a fashion that they don't mind you charging much more than a FTE over the same interval:
+ They can keep you for exactly as long as they need you, and then let you go, with no hard feelings.
+ You don't require a 3 ~ 6 week spin-up period as you get used to e.g. how your new employer uses source control, the procedure for running acceptance tests, or the proper way to fill out requisition forms.
+ The search to find you took days, not months.
+ The interview(s) to bring you in takes one person minutes/hours rather than several people days.
+ The paperwork to bring you in takes minutes, not days.
+ There are some specialties where FTEs for that specialty are either a) extraordinarily expensive or b) unavailable for hire at essentially any price. The business might not be able to justify keeping one of them around for the year, if for no other reason than their salary would upset the apple cart with other employees, but might still get value out of tactical engagements.
+ Employers and employees have an expectation that employees will occasionally have issues which temporarily impair productivity and that this is just the nature of the beast. ("Dad is in-and-out of the hospital and I'm mentally checked out.", "Off to JavaOne this week.", "I'm pregnant, cya in a few months.", "We sprinted hard for the last six weeks and I'm in cooldown mode.", etc) Consultants sometimes have impaired productivity, too -- but employers don't have to pay for it, since consultants will typically attempt to avoid scheduling engagements during them.
* Consultants put up with a lot of things by charter which are socially awkward to ask of employees, for example, "We need you in Berlin the day after tomorrow."
+ They can keep you for exactly as long as they need you, and then let you go, with no hard feelings.
+ You don't require a 3 ~ 6 week spin-up period as you get used to e.g. how your new employer uses source control, the procedure for running acceptance tests, or the proper way to fill out requisition forms.
+ The search to find you took days, not months.
+ The interview(s) to bring you in takes one person minutes/hours rather than several people days.
+ The paperwork to bring you in takes minutes, not days.
+ There are some specialties where FTEs for that specialty are either a) extraordinarily expensive or b) unavailable for hire at essentially any price. The business might not be able to justify keeping one of them around for the year, if for no other reason than their salary would upset the apple cart with other employees, but might still get value out of tactical engagements.
+ Employers and employees have an expectation that employees will occasionally have issues which temporarily impair productivity and that this is just the nature of the beast. ("Dad is in-and-out of the hospital and I'm mentally checked out.", "Off to JavaOne this week.", "I'm pregnant, cya in a few months.", "We sprinted hard for the last six weeks and I'm in cooldown mode.", etc) Consultants sometimes have impaired productivity, too -- but employers don't have to pay for it, since consultants will typically attempt to avoid scheduling engagements during them.
* Consultants put up with a lot of things by charter which are socially awkward to ask of employees, for example, "We need you in Berlin the day after tomorrow."