The Guardian has a spread about the cost of season tickets across the Premier League and the cheapest and most expensive tickets by club are as follows:-
Arsenal: £985 - £1955
Aston Villa: £325 - £595
Chelsea: £595 - £1250
Everton: £443 - £672
Fulham: £449 - £959
Liverpool: £725 - £780
CITY £425 - £745
Utd: £532 - £950
Newcastle: £363 - £707
Norwich: £547 - £608
QPR: £499 - £949
Reading: £525 - £595
Southampton: TBC
Stoke: £399 - £599
Sunderland: £425 - 525
Swansea: £449 - £499
Spurs: £730 - £1845
WBA: £349 - £449
West Ham: £600 - £850
Wigan: £300 - £350
So there are only 6 clubs with cheaper cheapest seat S/T's and there are 9 clubs with more expensive most expensive S/T's.
I don't think we're doing too badly given the football we've seen over the last 2 seasons, the players we have playing for us and the fact that we've won two trophies during that time and are Champions.