TL;DR Almost certainly yes.
Umbraco is an Open Source Content Management System (CMS), and is free for anyone to download and use for any purpose. It's designed for use on Windows Servers and compared to other leading Windows CMS's such as Episerver, Sitecore and Kentico, which are all proprietary, meaning that a substantial saving can be made in license fees.
That doesn't mean it doesn't cost money to build an Umbraco site. There are costs including hosting, development and third party plugins, but these fees are no cheaper on the proprietary platforms and so in almost all cases Umbraco will be cheaper.
In comparison to other Open Source CMS's such as Wordpress there are usually fewer, if any, savings to be made. In fact entry level sites can be sometimes be lower cost on Wordpress as the developer skills are more ubiquitous, and so small, local agencies and sole developers can deliver entry level sites for less. However, as the scope, level of design and budget for a project increase then the cost differential between Wordpress and Umbraco begin to level out.
If you'd like us to give you an estimate of the rough costs of developing your next project then contact us.