Shropshire Council and business bosses once again defended the decision to buy the centres after the latest valuation figure was revealed.
The overarching plan is for the Darwin Centre to be the main shopping precinct, Pride Hill Centre to become the new council HQ and offices downstairs with a leisure facility upstairs, and the Riverside Centre to be demolished to make way for a new riverside destination - a major part of Shrewsbury's Big Town Plan.
The council has faced heavy criticism over the purchase, but Mark Barrow, the authority's executive director of place, insisted there was a bigger picture to consider.
He said the valuation of the centres is what it is "for a moment in time", and is optimistic that developers will be keen to invest in the town and be part of a huge revamp which could cost around £800 million.
The Darwin Centre is on track to be "97 per cent full", with new tenants waiting in the wings, he said.
Mr Barrow believes that if the authority had not bought the centres, the town would still have malls full of empty shops.
He said: "If those centres went into private ownership, you would still have centres with holes all in them. I think we have done the right thing."
Councillor Ed Potter, cabinet member for economic growth, regeneration and planning, said: "I feel it was the right decision to make. We need to show that we want to invest in the county town. We're not just for Shropshire. We have a lot of visitors that come from outside Shropshire. We're prepared to put our money where out mouth is."
Kevin Lockwood, manager of the shopping centres, said: "I feel more safe talking about the positives now the centres are in Shropshire Council's ownership."
When asked if the council could have waited a year or two and picked up the centres more cheaply, Hayley Owen, from the council's growth programme and strategy manager, said: "It might not have been possible," citing that circumstances may have been different, such as the properties not being on the market.
A planning application has been lodged to demolish the old Riverside Medical Practice, and Mr Barrow insisted more significant steps relating to the riverside development are on the way.
Asked whether the controversial North West Relief Road is essential for the town centre redevelopment, Mr Barrow said: "It helps us bring forward plans."