Just read the BBC Sport Price of Football survey 2012
"The average cost of the cheapest adult ticket in the top four divisions of English football has risen by 11.7% in the past 12 months"
http://i47.tinypic.com/33xx7qa.jpg
Our lowest season ticket price is actually quite disgusting but this is obviously because demand is higher than supply.
The only thing that is a given is that some ticket prices will be significantly increased, while others might actually drop in price, once the ground is redeveloped.
Current season ticket holders will get first choice.
e.g. Half way up near the centre of the pitch in the main stand will be premium seating. I would expect £900 - £950. I also wouldn't be surprised to see higher priced tickets (ie double) that also include suite options. Obviously they would be limited in supply, and only if there is demand for it.
I would expect high up seats in the corner to be cheaper than they are now, so that statistically the pricing looks fair. e.g. A few hundred seats that are available at £500 - £600
I'm just making up figures, but I am just gob-smacked at the prices at Arsenal and Spurs. Arsenal's does include 7 potential cup vouchers, so the price isn't representative for a direct comparison, but if you deduct £200 for the extra matches its still £785 for the cheapest ticket.