There is always a debate between whether conservatory buyers go for “my local prices conservatory price guide” or to a National coverage installer prices guide for quotes.
The main contention being that a smaller, but no less professional company has less overhead than a big company and can therefore offer a better deal on a given type of conservatory.
The premise that local prices are lower than National prices has some merit.
Firstly, the local company is based where you live (or not too far away) and will be aware of the market prices in your location, something a big company may not be too aware of.
The local guy will probably done some work not so far away from your home and can easily refer you to the customer to vouch for their work.
Being in the local market, almost forces the local business to keep prices keen, as they want to build a strong business and can;t afford to lose local customers.
Aside from the price factor, you could get a more personal response from them. Large companies with thousands of clients have garnered a reputation for not “caring as much” for customers as local businesses. I suppose, at the end of the day, the proof in terms of pricing will only come when you get quotes form both and compare them to see which is the best deal for you.