First of all you need to read the advice on this page of my website:
The do's and don't when buying a new home.The two most important things are NEVER use the housebuilder's solicitor and have the home professionally snagged and inspected before you legally complete.
As for price, you should check selling prices on Rightmove and Zoopla for other homes in that area.
Barratt and other house builders always have room for a discount or deal, especially at their financial half-year and year-end. But Barratt's is 31 December and 30 June.
I would be very suspicious this house is 100% finished yet has no buyer. Ask sales why?
It could be that the buyer pulled out at the last minute.
It could be that it is a plot no one wants (except you!) meaning you will have trouble to sell it when the time comes. Perhaps it faces the wrong way, has social housing next door or nearby, or is overlooked, no garage etc etc.
Be ware that sales staff have been known to lie through their teeth to get a reservation and their commission. Make sure you get everything they say audio recorded or in writing.
Too late to order carpets? That's a new one on me. Question why its too late?
Do they expect you to come back with the cash in a bag and move in in a few days?
You will have at least 28 days before you exchange contracts then you have to legally complete, although both could be done on the same day. So there is plenty of time for carpets!
But you would be better getting your own carpets as builder's carpets are always rubbish quality, especially when thrown in for 'free' on a deal.
You need to be very careful you don't get carried away with this. Ask lots of questions. Make an informed decision. But be mindful that as this home is ready to move in someone else may beat you to it too and Barratt may also suggest this when being firm over further discounts.
Having said all that Barratt are one of the better housebuilders for quality and customer service, but that's not to say you won't have any problems with either your home or with them.
They aren't necessarily "good", just that the others are so terribly much worse!