I would not purchase software through ShareIT for a while because of their currency exchange inaccuracies. They insisted that their policy was not to charge anything extra for currency exchange, but when they converted Euros to USDollars, it looked high to me. I checked at several international banking websites and it turned out that they were adding from 4% to as much as 9% to the price when converting! I wrote to ShareIt and to their parent company, Digital River to complain, but they said they could not comment.
Additionally, prior to that discovery, whenever I did purchase through ShareIT, American Express would call me at home and ask me several questions to verify that I indeed was making a purchase using ShareIt, and ti ensure I was aware of exactly what they were charging me. This always made me apprehensive also. A written request as to why they did this got me a response that a very high incidence of fraud had been experienced with ShareIt purchases.
Now if I must use them I use PayPal, which Digital River added as an option to ShareIt purchases a few months ago. PayPal allows me to pay in US Dollars and then THEY make the conversion. Works for me!
But if you are in the US and using a credit card with ShareIt, check the conversion rate very closely!