The corporate seats are maxed out with a few to spare - that includes the Main Stand, Kenny Dalglish and Anfield Road Ends (the latter using the Isla Gladstone, Sandon etc etc)
The available footprint within sight distances and without building in the corners would yield a stand at about 13,000 or less at new leg rooms. Same number of hospitality seats as now. A net increase of about 4,000 - all of which, General Admission. Maybe minus a few season tickets off the list.
The club has no appetite for cheaper seats for General Admission and at the same time cover the cost of a completely new stand.
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The best option is to keep the ARE lower, build on the back (per the planning consent), continue to use the outsourced hospitality facilities or bring them into the ground.
If the lower ARE is kept, then theoretically there might just maybe be room for cheaper seats but it is highly unlikely because of the cost of losing the 2,440 seats in the ARE upper and the cost of building the new seats.
Going to the match is not going to get cheaper as long as the club has major works to pay for.
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I've seen nothing to suggest that the club won't just build the existing planning consent as is, when it can afford to (when the main stand is paid for)