Personally, I use a Price Spike Limit that is around 150% of the average estimated earnings per card. Using your example, I would set a limit of $4.50 for a GPU that averages $3.00. That amount provides some room when values rise, but avoids work that is going to draw a lot of attention from other miners and is most likely based on an inaccurate data.
I really think that the x11 price issues on BlockMasters have hurt your earnings. Since x11 is heavily mined by ASICs, it is almost never profitable to mine on GPUs anymore. I have kept x11 disabled on my rigs and I have made more than $1 a GPU in the last eight hours on that one pool plus earnings on a couple other pools. If you have already upgraded to 1.8.8 of Hash Auger, you may want to enable the MC Parameter for BlockMasters. I have found that individual coin prices are better on that pool than the traditional auto-switch ports. The only issue is that the C11-based coin ChainCoin has some issues on that pool, so you would want to disable the C11 algorithm on BlockMasters.
A couple other tips to possibly help your earnings would be to try a slightly longer switch interval by increasing the Pool Refresh Rate to 15 minutes and to set the Min Price Switch % to at least 12%. These settings can help you build larger shares in new coins and help offset the cost of switching work too frequently.
If i look now i see lyra2z suppose to give me around 3$ a day with blockmasters
If i look at Aweseome miner they say 1.42$ a day, almost exact same hashrates.
Hard to see which one to trust atm