I have been working with OpenGTS & GTS Enterprise (GTSE) for 2 3/4 years, and currently provide support on an ongoing basis for 12 customers.
My experience with OpenGTS includes, installation, configuration, customization, Device Communications Server (DCS) development, testing, and training, so yes it is a walk in the park..
The fee quoted in this proposal is to install, and configure OpenGTS, and other required software on your host. Also included are configuring of the mapping provider, reverse geocoding provider, DCS, and email.
This quote also assumes that your requirements are supported supported by OpenGTS as it is downloaded from github, without any extra modifacations, and assuming you will be using the DCS(s) provided with the package.
The 7 day lead time is to allow for lags in communications with the various providers involved, insure that the installation is working correctly, and so you have been provided some training.
The $315 USD price tag is what I charge for a basic installation, as there will be other packages which need to be installed before OpenGTS will work. These packages invlude MySQL, Java, Ant, Apache Tomcat and others, please understand