Tough to say where that pricing will shake out on the Integrity and Infinity.

You have looked at some nice samples there of the different materials.

Make sure you are comparing installation details in the same capacity.

You are looking at three product materials with different pros and cons. I can say that each product that you've seen is highly regarded, but for very different reasons. You will want to assess your priorities for the project to determine which is the best fit. All are well made quality products.

-Performance?
-Appearance?
-Cost?
-Value (very different than cost)?
-Warranty?
-Longevity?
-Option content?
-Perception by others (including guests and/or future buyers of your home)

If I could make a chart, the Okna would skew toward performance, value, cost, and warranty, the Ultimate toward appearance, perception, option content, and the Integrity/Infinity as somewhat of a bridge between the two. Not as good in the "good" areas of each choice, but not as bad in their weaker areas either. Whether that makes it a "glass half-empty" or "half-full" proposition depends on your perspective.

... let me add that those Pros and Cons are regarding the comparison of these specific products and their respective materials. For instance, the Marvin product line is actually a very good performer as WOOD products go, and the Okna is very attractive as VINYL products go.
My recommendation would be to pick the material that best suits your needs/goals FIRST, and then pick the product line. :)

Thank you both for your reply. I really appreciate the feedback.

@ windowsonwashington - can you please provide me with some advise as it relates to comparing installation detail? Do you mean new construction vs. replacement? or the way in which they actually install the windows (materials used etc)?

Thanks