Difficult question to answer withour more information, but let me start this way:
Web-based training is generally classified into three levels of complexity (level I, II, and III), with the chief differentiator between these levels being how much interactivity is required to effectively meet the educational objectives. Pricing varies significantly based on level. Best practice is to estimate the level and have vendors price for an hour of training - courses can vary in length, but the number of screens created drives the length of course and level of interactivity, and cost for the vendor.
Most organizations I know price Instructor-Led training on a per day basis.
One other consideration is the determination of the split between web-based and instructor-led. Blended learning is still as much art as science, but selecting a targeted number of hours of web-based learning at say Level II and a number of days of instructor-led training gets all the vendors bidding on the same general solution.
Of course, if you need the vendor to provide a delivery Learning Management System (LMS) to deliver the web-based training, this is an entirely new topic.
Hope this helps.