I hate loaded questions with complicated answers but here goes.
The answer is it depends.
Normally engineered beams are used with normal dimensional lumber joists or 3" tongue and groove decking. They are used where the span is greater than can normally cut with dimensional lumber or where greater loading is required. This is the most expensive method of construction.
Engineered joists or trusses (there are different designs) are used where longer spans are needed and in replacements to normal joists. They are generally more expensive than regular joists.
Dimensional are the least expensive but you are limited in the span.
These are the costs to get the floor decked. Unfortunately the cost of contruction is something entirely different than the cost of decking.
For example the engineered joists may cost more than regular joists but the deck may have less variation and greater flatness. This effects the rest of construction and may lower the cost of construction. The truss style joist has passages for wiring and plumbing that allows quicker secondary operations.
If you are spanning larger areas then the engineered beams many actually cost less than building support walls or posts in the basement.
Depending on the finish required then the engineered beams and the 3" decking may be less regular joists and tongue and groove.

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