I think that an image of your future home will help people understand what type/size windows are in question.

Give more details, get more bids. possibly explore there lower lines and other brands. I’d do a bit of research before dumping 150k on windows. Getting bids on windows for a new build is typically pretty simple.

Is it possible that a bunch of those "25" are twins, triples, have transoms, etc? If so, counting the pieces that make up those units will give you the qty that you are looking for to do a "per window" comparison.

If those are indeed 25 single windows, I'd recommend trying another Marvin supplier.

Since it appears that you are going to have to compromise your choices, make a list from most important to least and share with your window (in this case, Marvin) dealer. Also set a realistic budget target that you want (easier said than done). In the case of Marvin, Andersen and other large manufacturers, the have multiple lines that you can mix.

I have many jobs where I have mixed Marvin products. Ultimate on the front elevation or the more important rooms and Elevate and Essential elsewhere. By staying with the same manufacturer's line, you don't have to worry about matching colors as they are consistent.

As far as use, doors are more important than windows. Put your money into the doors and be "fussy" about installation and easy operation or you will always regret it.

It's 150K because he can get it. He doesn't care if you walk; plenty more just like you waiting.

My prices are nonnegotiable. Take it or leave it; we're at capacity.