I have looked at this similar question but I think my problem is a little different.
I am using Geth to try and send 0.9 eth from one cli wallet to another, using this command in my bash shell terminal:
sudo geth --exec "eth.sendTransaction({from:eth.coinbase, to:'9866c73a755da3d434cfdc8bca8fed02eebad469', value: web3.toWei(0.9, 'ether')})" attach
I currently have 0.99 Ethereum in my wallet, so I should have enough to do the transfer. I am using the mainnet. I left the gas amount blank so that geth works out how much I need to spend.
What am I doing wrong here?
{from: eth.coinbase, value: amount gas: amount ...
. A lot depends on the receiver, so this experiment will help rule out incorrect gas estimation.