In my experience, a properly done stain job will be no less expensive than a factory finish, and can be more in many cases depending on how discerning you are about the final product. A furniture grade finish requires quite a bit of prep work and several coats of sealer, stain, finish, etc and can take hours per window. That said, the factory finishes are decent and good enough for most people. You can probably figure a range of anywhere between $100-$300 per window for staining depending on the size, configuration, and quality. Much lower than that could be sketchy.

Hmm, so in fact an approximate cost of $200 per window for factory staining is right in the middle there.

Apart from wanting to stain the windows something not available from the factory, would there be any reason to stain in the field?

Thanks,

Nitin

A higher quality finish can be had by custom-staining. Again, that is not to say that the factory finishes are bad, as they are pretty good and satisfy 95% percent of clients, but they just are not as intensive as a high quality custom stain job.