Specify base 10 in bignumber

app/scripts/lib/id-management.js

@@ -28,7 +28,7 @@ function IdManagement (opts) {
     //  calculate gas with custom gas multiplier
     var gasMultiplier = this.configManager.getGasMultiplier() || 1
     var gasPrice = new BN(ethUtil.stripHexPrefix(txParams.gasPrice), 16)
-    gasPrice = gasPrice.mul(new BN(gasMultiplier * 100)).div(new BN(100, 10))
+    gasPrice = gasPrice.mul(new BN(gasMultiplier * 100, 10)).div(new BN(100, 10))
     txParams.gasPrice = ethUtil.intToHex(gasPrice.toNumber())
     // normalize values
 

ui/app/components/pending-tx-details.js

@@ -32,7 +32,7 @@ PTXP.render = function () {
   var gasMultiplier = txData.gasMultiplier
   var gasCost = new BN(ethUtil.stripHexPrefix(txParams.gas || txData.estimatedGas), 16)
   var gasPrice = new BN(ethUtil.stripHexPrefix(txParams.gasPrice || '0x4a817c800'), 16)
-  gasPrice = gasPrice.mul(new BN(gasMultiplier * 100)).div(new BN(100, 10))
+  gasPrice = gasPrice.mul(new BN(gasMultiplier * 100), 10).div(new BN(100, 10))
   var txFee = gasCost.mul(gasPrice)
   var txValue = new BN(ethUtil.stripHexPrefix(txParams.value || '0x0'), 16)
   var maxCost = txValue.add(txFee)