Doors and Windows - Sash Replacement Kits -- Need Info -- Anyone used them?

After lots of research I have decided to buy sash replacement kits to replace my very very old single pane wood windows due to low cost and high investment return on heating (I live in Minnesota and was the victim of a 400 dollars gas bill in one month this winter). I have looked very heavily at the Marvin and Weather Shield. My windows are about 58 X 26. The thing I like a little more about WS is that they have a optional oak interior but I haven't explored pricing yet. I was quoted low 200 for double pane Marvin with Argon filling. Here are my questions:

1) Has anyone had experience with ANY sash replacement kits (especially Marvin or Weather Shield)?

2) Is it actually a do it yourself project for someone who is somewhat handy?

3) I would embrace any other comments or help as long as no one yells at me for replacing my old windows, I can't have another high priced winter again.

Please give me any advice you can. Thanks in advance for any help you provide. I will listen to your advice and/or experiences with great interest. Thanks again.

Hello ncasper,

I am in the midst of replacing my old windows as well and I looked into the sash replacement kits. The word that I have been getting is that they are not as good as going with an entire retrofit replacement window because they are three separate peices which can allow for more draft infiltration. But maybe it just comes down to personal choice.

I think the Marvin's are good but I have no experience with them.

I have decided to replace the entire window with a retrofit instead of a sash kit and I am going middle of the road due to budget restraints.

Good Luck!