Could you please explain variance and how it affects an entry-level miner?
Not directly answering your question (see post above mine), but some basic info on why p2pool has such a high variance:
Solo mining requires you to find a "share" (proof of work) with difficulty equal to or greater than the Bitcoin network difficulty.
p2pool is a separate network where the block creation time target is set to 10 seconds instead of Bitcoin's estimated 10 minute block time.
The result of this is that it's a lot easier to find a p2pool block than a Bitcoin block because the p2pool network difficulty is much lower than the Bitcoin network difficulty.
p2pool blocks merge mine Bitcoin blocks: that means a valid p2pool block is also a valid Bitcoin block, however the valid p2pool block must meet the Bitcoin network difficulty in order to be accepted on the Bitcoin network.
What happens in p2pool is you mine p2pool blocks, called "shares", by finding a hash that has difficulty equal to or greater than the p2pool network difficulty. If the share also happens to have a difficulty greater than or equal to the Bitcoin network difficulty, then the share is also submitted to the Bitcoin network and everyone using p2pool who has recently submitted p2pool shares (hashes >= p2pool difficulty but maybe less than Bitcoin difficulty) get paid from the block.
However the system isn't perfect. p2pool blocks are found 60 times faster than Bitcoin blocks which means the difficulty should be much lower, however many people are now using very powerful mining hardware so the p2pool difficulty is still quite high for small miners. You only get paid when you find p2pool shares and with 6.5 GH/s it will take a very long time to do this. You should see a "expected time to share" value on the p2pool stats page (if you are running it locally) which should give you an idea of how long it may take before you find a payout-earning share.
Hence you will have better luck using a regular pool. Most regular pools can accept shares of any difficulty and usually automatically adjust the share difficulty based on your mining speed so you should see consistent (although small) payouts depending on the overall hash rate of the pool.
Good luck!