Would be interesting to see a scale of cost v capacity - guess someone somewhere has done this and knows what the optimum no. of seats is.
Fans will always want the biggest stadium possible but the decision around capacity needs to factor in how long it will take to pay off the build cost. For example, if it was a:
- 45-50k state of the art, iconic stadium which takes 15 years to pay off and is always sold out (with scope to easily extend in future IF required)
- 55-60k with perhaps a slightly lower spec which takes 25 years to pay off and isn't always sold out or means reduced ticket pricing (thereby bringing gates receipts equivalent to the above smaller version)
Purely made up figures of course but if the difference in build cost between the two (10k seats) was say £100m that could equate to £150m+ in repayments when you factor in the £7m a year to LCC + interest if paying that bit (applying the multiple loans example) back at £20m per annum.
Heck of a difference financially if you look at it that way.