In the last couple of weeks I have through word of mouth been put in touch with two local nurseries both having a good range of veg plants and seeds, compared to the large garden centres that do a similar range they don't come anywhere near, so I say support your local nurseryman :)
We have a few family run nurseries here, most have good quality plants, not bad prices but I'm lucky enough to be able to go to a grower direct nearby. His plants are fantastic quality and price. I'm all for supporting local business if the product is good.
If you can find such places, treasure them!
Yes I have bought a few things from our local nursery. even though it is a bit more expensive, I found that the plants are good quality and they give you good advice on things. They sell hard to get things like green manure seeds by weight. They give good quality service so they seem to have a solid customer base. I don't say I go there systematically (I admit that as summer goes on I do go and look at the local hypermarket garden section because they sell off the excess plants cheap and I often get good bargains for things where I am not so fussy about teh variety, like salad stuff), but when I wanted to buy herbs and rhubarb, I went to the little shop because i knew it would be better quality.