Find a Local Quoter at https://www.cheapupvcbifolddoors.co.uk/how-much-do-upvc-bifold-doors-cost/that can give you the best deals on new doors as well as a double glazing price to match your budget.
New and Replacement Front Doors
What about the cost of a new front door?
Your material choice is going to make a difference to the price, because a softwood front door is going to be the cheapest and at the top of the range would be composite or aluminium front doors – read more: https://www.doubleglazingpriceguide.org.uk/residential-doors/fully-fitted-doors-prices/