I would say that the fact is 'saving' is singular and 'savings' is plural. This dictates the verb that follows. You could say A saving of $20 is ... or Savings of $20 are ...
A basement bathroom can be built for about $15,200, Fred estimates. Of that, plumbing is the largest component. These prices are based on costs for a small bath measuring about 6 by 8 feet, with 8-foot ceilings. However, many basements are limited to a 7-foot ceiling. Another potential cost-saving location for a new bathroom is the attic.
Typical Pricing. You'll spend at between $3,000 and $6,000 to convert a space like a garage or attic into a new bathroom. According to 2009 information from the Costhelper website, you'll spend at between $3,000 and $6,000 to convert a space like a garage or attic into a new bathroom. However, conversion costs can get as high as $25,000. If you're starting from scratch adding new square footage, you'll probably spend $25,000 to $50,000 or more for a basic 6-foot-by-8-foot room. A 10-foot-by-12-foot bathroom with higher-end amenities and fixtures like a spa bath carries an average cost of $73,145.