We have a 180 sq ft bonus room attached to the rear of the house. It is fully insulted and has finished walls/ceiling. However, it does not have heat or normal windows (just very old storm windows) and it cannot be entered through the house (it has a single exterior door). We live in Connecticut and are looking to make it more usable in the winter. We think replacing the storm windows (9 total) with vinyl replacement windows would be a good start.

So with that said, we see 2 possible options going forward.

1) Purchase cheap with the idea that any window is better than what is currently there. Local suppliers have quoted me for $200-300/window for brands such as United Window and Atrium. Also there's the in stock options at Home Depot which has American Craftsman 70 series for $178/window and Lowe's which has Pella Thermastar for $240/window and Reliabilt 3500 $285/window. Of these options, I've actually found that the Reliabilt 3500 is a re-branded Atrium and has the lowest u value & SHGC. Other than a bunch of poor reviews for American Craftsman, I cannot find much information on any of these windows.

2) Save up and buy a more reputable mid tier brand. Though I will admit I am very hesitant to buy more expensive windows in a room that does not have any heat (aside from a tiny space heater) and will not be used daily (mostly to entertain and occasionally hang out in). We actually faced this exact decision back in May when we replaced all the other windows in the house with Marvin but opted not to do the bonus room due to cost vs value.

What do you all think? Is there any cheap vinyl window brand out there that you would recommend that's under $250/window? I'd like to think I am not completely nuts for wanting to purchase cheap windows in this situation?

P.S. I intend on installing the windows myself to cut down on price.

Thanks!