The daily transaction limit is 20,000 USD, and the monthly limit is 50,000 USD, including fees.
The same limits of 20,000 SUD apply if the purchase is made in another currency - it is just converted to the currency used.
Please note that the total daily limit is calculated as 24 hours since your last purchase, not as a calendar day.
The total monthly limit is calculated as 31 days since your last purchase and not as a calendar month.
It is not possible to increase the set purchasing limits.