You may or may not get a "better" price on the stove buying it independently.
However:
The installer will it be liable for any product faults, that would be down to the retailer. If the retailer is an "online shop", then, good luck with that. They will generally (and possibly illegally) refer you to the manufacturers, and they (manf) all have different policies regarding attending to alleged product faults.
Secondly, the installer may have quoted a specific installation price on the assumption you were purchasing his product. Not all shops will fit products bought elsewhere.I had a gas fire shop, and we strictly only fitted our own sales. You would not go to a Magnet kitchen showroom, and ask them to fit a kitchen from the 'net. But it is for you to ask.
However:
The installer will it be liable for any product faults, that would be down to the retailer. If the retailer is an "online shop", then, good luck with that. They will generally (and possibly illegally) refer you to the manufacturers, and they (manf) all have different policies regarding attending to alleged product faults.
Secondly, the installer may have quoted a specific installation price on the assumption you were purchasing his product. Not all shops will fit products bought elsewhere.I had a gas fire shop, and we strictly only fitted our own sales. You would not go to a Magnet kitchen showroom, and ask them to fit a kitchen from the 'net. But it is for you to ask.