I did check Lowes at the weekend. Some annuals were about $6, also. I was only interested in the petunias and calibrachoa. Maybe half-gallon size pots. The azaleas there are also $14.99, like Home Depot. Nothing outrageous price-wise.
But I usually grow my own petunias anyhow (I collected seeds from one years ago and they are still super-fertile, so that was a good investment getting years and years of blooms for a single investment of less than $5). I plan also on collecting seeds from the one I bought at the weekend (night sky petunia - gorgeous).
However, my local Christmas Tree Shop I did notice their plants outdoors were a little more expensive than last year. Supermarket plants were a little higher also.
But I am not sure if that is specifically because Mother's Day is coming and they are cashing in on desperate kids, or whether it is a regular price increase.