Have Experience first.

SAP has authorized partners which take 5-6 lakhs for the training+certification. There are online/unauthorized trainers as well but whether you do 6 lakh course or 20k course theres no guarantee of job.
If you have exp companies ask for certification, when you have cert they ask for experience.

sure , now every company use ERP application whether it is SAP or Oracle EBS R12 ... ... you can do that course :-)