I bought a Positive SSL Wildcard Certificate from SSLPoint (reseller of Comodo) for $89/year.
You receive from Comodo:
Root CA Certificate - AddTrustExternalCARoot.crt
Intermediate CA Certificate - COMODORSAAddTrustCA.crt
Intermediate CA Certificate - COMODORSADomainValidationSecureServerCA.crt
Your PositiveSSL Wildcard Certificate - STAR_simple-landlord_com.crt (your domain here)
rename STAR_simple-landlord_com.crt to cert.pem
concatenate (just in notepad) together:
AddTrust