You can use existing drives which you were using in MSA 2040 and that will save your cost. Provided all drives are supported with MSA 2050 otherwise you can't use any unsupported drives in MSA 2050 from MSA 2040
MSA 2040 and MSA 2050 both are different but still you have option to move your existing data from MSA 2040 to MSA 2050 with applied conditions.
If you really want to discuss about your specific requirement then it's consultancy job for which you need to contact HPE. This is public forum and limited information can only be shared to give you idea only.
Hope this helps!
Regards
Subhajit
I am an HPE employee
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