This is just non-sense. If a host offers a 30 day or 90 day free trial with their packages that is an option and it is not them been cheap nor cutting corners. It's simply an offering of a trial of a product within their service and wouldn't low ball with such statements while "throwing" in what "you offer" just prior to that - with all do respect.
Back to the OP
As mentioned before there absolutely nothing wrong with using that trial certificate in fact you can probably go directly to any SSL provider and get a trial straight from them if you are looking for a specific one or try others. Once that trial is over you can go through any provider for that SSL.
The SSL certificate is not tied to your provider whatsoever, however there is something to keep in mind.
- Check with your provide if they support SNI this will save you a bit of cost as you will not need a dedicated IP to install the certificate.
- If they don't offer SNI, check the cost of the dedicated IP.
There are multiple SSLs and their pricing will very depending on the features. GeoCerts has a wizard that will walk you through choosing a certificate if you don't want to spend time going through and comparing, (
https://www.geocerts.com/wizard)
Here is a good article for beginners on the bare basics.
https://info.ssl.com/ssl-made-easy-for-beginners/