Good day,
With an experience that exceeds 18 years in elearning, part of it which is SCORM of which I had a coding experience since 16 years.
For your project, I do understand that you have a bespoke LMS, the SCORM player would not be easy to implement as it is not just a little code to be added and it's done, no it is too much more than that, so you should expect that it should cost starting from $2000 depending on the feature set you are implementing.
There are many factors to be considered including that there will be modifications to your LMS structure, coding, database & etc.
I can assure you that other bids on this project are just generic and does not have a value.
For discussion on this project, kindly initiate a chat with me.
Best regards,