you probably don't have enough to make the payment and also cover the fees. go to your preference and enable the fee options, that way you can see how much fee you are paying and also you will be able to edit it.
make sure to check out
http://bitcoinfees.21.co/ to get the feeling what fees are appropriate at any present time for a fast confirmation. right now it is 167,240 satoshis, if you are not in a rush to make a purchase,... then wait a couple of days for this issue to be solved and fees come down. it will most probably be solved in a couple of days. if not you have no other choice other than paying the high fee.