That's almost 50% for buying 1000. I also wanted to make a purchase of BNB tokens worth Rs. 200 via Wazir via UPI but it had disabled UPI payment mode for a long time after which I uninstalled it. I just needed this to pay for the network fee.
I do not think any Indian exchange is offering UPI payment. The minimum amount to make a purchase using Metamask is INR 10K and the percentage of the fee reduces if you make a big purchase. In anyways Metamask is again following what the Indian government wants because of the chosen payment processor. I won't recommend you Metamask for any purchase as of now as they will ask you to pass KYC.