There is a perspective to this in that Crystal Palace revenue for the 2013 season in the championship was under £15 million, finishing 11th last season saw the prize money for that position at £74 million, staying in the PL over the next few years will given that they control wages and player recruitment leave them substantially better off financially, there are additional rights packages coming up as well that will further boost PL income. Saying that Pardew will never have the finance at Palace ignores the way in which Ashley has controlled the purse at NUFC and pulled the rug out from under with the sale of the better players and goal scorers that any club needs to compete, watching Palace over the last 4 games they have shown that they have pace, goal scorers and have come from behind in 3 matches to win, something that Warnock couldn't get them to do, yes it is early days but this is a team that finished 11th last season and have some decent players as they showed against Liverpool last season they are capable of competing rather than just being bottom of the table scrappers.
I think the problem is their capacity to expand in the short term. They have a good youth system which could stand them in good stead. A few more Nathaniel Clynes could see some quick progress financially. I can't see them spending much in the near future. Possibly like you say, 2 or 3 years down the line if they can maintain a few mid table finishes. The margins between 11th and relegation are fine though so in the short term he'll be up against it. We know they aren't about to release funds because it was one of the reasons Pulis decided it wasn't for him.
So for me anything Pardew does in the short term (2 or 3 years) which sees them not fighting relegation is a feather in his cap.