If your email volume is low, Mailgun allows you to send 10,000 monthly emails free of charge but you need to give them your credit card. As soon as you go over that, they may charge you $0.5 per 1,000 mails.
I usually pay betwee $3 and $4 dollars for ~30k monthly emails on AWS SES.
The first time you install your addon on the new PC you should install it either from the CLI or Admin CP. After that all you have to do is import the development output directory as instructed here (https://xenforo.com/xf2-docs/dev/development-tools/). Make sure to include the _output directory...
A quick search returned the following resources that you might find useful: