Yikes! I don't understand the size/age calculation to determine if the client will include the trans in a block.
It goes (btc in satoshi*confirmation)/size in byte > 57600000
So if you want to send 10btc with a standard sized transaction of 250 bytes:
1000000000*x/250> 57600000
--> x > 14.4
So you will need at least 15 confirmations to send 10 btc for free with fast confirmation.
If you send small amount like 0.001btc:
100000*x/250> 57600000
--> x > 144000
This is why it takes forever for small transactions to confirm.