The certificates game has changed and admittedly I have not kept up. I do know that there are companies providing certificates that are less than trustworthy. Certificates are evaluated and part of that is the reputation of the issuer. It is possible that a certificate is rejected because the issuer is not trusted. If you feel confident about the certificate provider, then I would go with that. If you are not sure, then I would shop around for an issuer with a good reputation. Make sure you are dealing with a reputable issuer to avoid issues down the road. The cost of a certificate should be minimal as far as I know.
I cannot see why a hosting company would not be competitive on it's price. I know some less than honest hosts provide hosting for free or cheap and jack up the prices for additional services. Having been in that business before, I know there were a lot of games played to lock a customer into continuing with the service and paying the higher price in order not to feel the pain of switching. Quality hosts do not do these things. Certificates are just a small part of the process and should not be so expensive. If your host fits into the category I described above, it may be better to just switch hosts. I know some offer incentives which have included HTTPS support and free certificates. I used to be a certificate authority along with my web hosting and I never charged for a certificate for any of my customer sites. It cost me nothing to provide the service and only took a click of a button to provide the certificate. In fact, it was a beneficial feature to be a recognized authority with a good reputation. It was a win win. Shop around. You may find a good deal.