One photograph retouched

I have one photo which needs retouching in Adobe Photoshop.
It is a vase of flowers shot against a painted background. The background was not large enough so at the edges the background needs replacing to match the painted background. Needs to look seamless, with colour gradation in line with the background as it is, and nice edges around the leaves/flowers on the right hand side.
Please note I don't want the entire background removed and replaced and I don't want any other alterations to the image.
Any questions please ask!
I would like a fixed price.