We do NOT use standard, out-of-the-box opportunity amount field in SFDC and RCE syncs with this standard SFDC "Opportunity" field. We have a custom field in SFDC that is formula based and populates global currency into USD. I called Marketo Support and they re-mapped the MKTO opportunity amount field to this new custom field. No luck - I believe MKTO can NOT read opportunity amount field that is formula based.
I'd appreciate if anyone can share how to set-up a custom opportunity amount field in SFDC that MKTO RCE can read. Thanks!!
Assuming that Marketo sees the field and the mapping is correct, you must re-sync that Opp (or Lead) to Marketo to see the latest formula. This is true of all formula fields in SFDC.