Customer Heather Byrne with tinsel
The 99p Stores was officially unveiled to the public at the former Woolworths site, in London Road, on Tuesday at 9am.
Customers crammed their baskets with cut-price items from cards and candles to toys and tinsel.
Heather Byrne, who stopped by on her way to work, said: "I knew about the opening, so I was going to come anyway. Hopefully it will be the beginning of a revival for East Grinstead. It's a pocket money store, so I think it's great for the town."
Customer Rachel Treeby added: "I popped in to get a few Christmas bits. It's really good for the kids, who have to take things into school. It's going to make things a lot easier, especially for young parents who are a bit hard up at the moment."
Clare Thayre said: "A lot of people need something like this in the town, particularly at this time of year. I want to go back in there already."
Staff spent three days filling the shelves in time to open on the first day of December.
99p Stores operations manager Srinivas Arumalla said the queue was a bit shorter than anticipated because of the cold weather, but the shop soon filled up with customers.
"It's been a very quick turn around for us," Mr Arumalla said. "We have had to do everything in three days. The good thing is it offers real value for money and has created a lot of jobs for the town."
Among the 25 employees at the new store are two former Woolworths staff.
Mr Arumalla added: "We have been growing very rapidly for the last year and still have another five or six stores to open before Christmas. Many of them are old Woolworths stores, because they are all located in excellent areas with a lot of space inside."
The East Grinstead store is believed to be the firm's 120th since it was founded in the UK in 2001.