The code had 3 separate places where high fee values are hard coded.

1. WalletModel::prepareTransaction in qt/walletmodel.cpp rejects transactions with a fee over .1 BTC initiated from QT.
2. nHighTransactionFeeWarning defined in wallet.h generates a warning in init.cpp if a fee amount over .01 BTC is set with -paytxfee
3. AcceptToMemoryPool in main.cpp rejects a transaction unless the override is set if the fee is greater than 10,000 times the minRelayTxFee (= ~.023 BTC for a simple 1 input, 2 output tx).

It seems like it would make sense to consolidate to one warning level and it should be significantly lower. (maybe 1,000 times the minRelayTxFee or just a fixed amount).

From the standpoint of reworking the UI (#5200) there should be a warning that you could click through to allow the higher fee. This would help address @petertodd's concerns in #4250.

Also it seems like AcceptToMemoryPool is an odd place to have this check, perhaps we could move it somewhere else to handle an rpc initiated transaction?