SSL certificates are available on reliable Certificate Authorities as well as trustworthy SSL certificate Resellers. Both Resellers and Certificate Authorities (CAs) offer same security, features, Encryption length, Warranty etc. for each SSL certificate. The only difference is Pricing.
You can also buy SSL certificates from CA authorized re-seller. Here is a list of some well-known SSL re-sellers sell a range of same SSL certificates at a much lowest price:
Namecheap.com
Cheapsslshop.com
Cheapsslsecurity.com
SSL2Buy.com and more.
Where Comodo standard SSL certs are available in the $6/yr. range and Wildcard SSL certs start at $40/yr and go up. Certificate pricing is applicable on 2 years SSL certificate validity purchase from authorized re-seller.
You can first start with blog post submission. Write a well-structured content for your product and explain every feature. You can also promote your product through Press Release, a well-known platform to support your product service and other business marketing aspect.
Apart from content promotion, you can use community, product listing, and social media platform. Paid advertising is also a popular channel to reach maximum audience within a budget.
I recommend you to try Cheap SSL Shop Reseller Program https://www.cheapsslshop.com/partner-program. They are offering huge benefits to their reseller partner, and also you can buy SSL Certificate for your website at the lowest price.
You can also buy SSL certificates from CA authorized re-seller. Here is a list of some well-known SSL re-sellers sell a range of same SSL certificates at a much lowest price:
Namecheap.com Cheapsslshop.com Cheapsslsecurity.com SSL2Buy.com and more.
Where Comodo standard SSL certs are available in the $6/yr. range and Wildcard SSL certs start at $40/yr and go up. Certificate pricing is applicable on 2 years SSL certificate validity purchase from authorized re-seller.