soundproof/thermal windows

I can't give you actual figures but in hot weather those windows help. walk in after being out and the a/c will cool faster when it's turned on. Warmer in cold weather when the heat isn't on in the building.

You will only get a benefit if you have old drafty windows in place and you pay your own heating bill. But if you have noise issues, they work like a charm.

Well there will be less need for a/c. That saves energy and money.

Had Citiproof install inner windows in every room of 3 bedroom/2 bath aparment with windowed kitchen, most rooms facing south. About 9 years ago, the cost savings were well over $100 per month in electic bills for both a/c and the fan for hot water heating system in winter. To boot, the noise reduction was mind boggling. It was well worth the cost. Great company, good advice on what best for your needs. Reliable, professional installation. Did not try to "oversell".