Cost of Blueprint Research is different for similar BPs - why?

Industry Gameplay Center Science & Industry
1

Can anyone explain to me why research costs of similar Blueprints can have huge variations even though the BPs are similar - same cost to buy off market, same location, same current ME/TE research - yet the PTV (Process Time Value) is calculated differently?

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Yet here is their PTV calc (TE +2):

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image352×277 20.3 KB

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image345×276 20.7 KB

How can one PTV be higher than the other?

2

Material price and quantity isn’t the same.

Process time value=Base duration_n×0.02105×∑all materials Material quantity×Material adjusted price

Edit: source is Eve uni → research-> cost of research