As mentioned earlier, every time you 'Add Funds' to your Reseller Account, your Total Receipts will increase. For example, say you have activated your account at $25, your Total Receipts will be $25 at that instant. If you then add another $100 to your Reseller Account, your Total Receipts will increase to $125. As you keep adding funds, your Total Receipts will increase consequently. Once your Total Receipts reach $499, you will be automatically upgraded to the $499Slab.
Let's say, you would like to directly upgrade to the $499 Slab, after having initially deposited $25, then you only need to add the difference amount of $474 to your Account.