I will definitely try that for testing purposes.
The coins were just a few days in my wallet when trying. Does it matter if the coins are freshly mined?
The coins should be mature (>100 blocks after coinbase) AFAIK.
There is a general rule as "1 bitcoin-day".
If your input is 1 btc, you will need to wait for ~1 day to have a high enough priority for a ordinary transaction (1 input + 2 outputs).
If you input is 0.1 btc, you will need ~10 days.
Thanks for the reminder of the actual numbers. In case anyone wonders about it, here [1] is a more in debt explanation.
[1] https://en.bitcoin.it/wiki/Transaction_fees#Technical_info