AFAIK conversion from string to number always assumes dot (.) for decimal separator and optional comma (,) as thousands separator for money. This is is not affected by collation, SET LANGUAGE, any of CONVERT styles or currency prefixes (€, £, ¥...)
For one-time conversion, REPLACE() won't hurt much.
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heisenbug: A bug that disappears or alters its behavior when one attempts to probe or isolate it
schroedinbug: A bug that doesn't appear until someone reads source code and realizes it never should have worked, at which point the program promptly stops working for everybody until fixed.
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