fee per KB calculation wrong

[raedah]

related to decred/dcrticketbuyer#58

https://mainnet.decred.org/tx/5161b980936ee934f0fc0025395bb91fdcd9b5fd89b8a77cc375c51159e7a46c

FEE: 0.07500000 DCR , SIZE: 297 BYTES , FEE RATE:0.25252525 DCR PER KB

0.25252525 * (297/1024) = 0.07324218

or are we suppose to divide by 1000?

0.25252525 * (297/1000) = 0.07499999925