When I was looking around those were upwards of $150+ The prices could've changed since then, but that's what I remember seeing
Well that may be because they're out of production now so they command a higher price on the used market. Although I'm not sure why, because for that price, you can get a Tournament Edition controller that uses the real arcade parts and is much better overall. Unless you were actually looking at a Tournament Edition controller in the first place. Mad Catz made two different SF4 controllers: a $60 standard edition, and $150 "tournament" edition.
However I also would like to say that a stick, while it is nice for fighting games, it is not necessary and that if someone only has a controller available to them, you can get pretty good with just a controller as well. There shouldn't be a need to pressure someone into getting a stick.
This is definitely true. Like I said, this game is very playable with a keyboard if you're on PC. In fact, I think that may actually be better than a gamepad. Since this is intended for new players, there are two main issues with the average gamepad:
1. Is the d-pad any good? If it's a 360 controller, the answer is hell no, but you can get other 3rd party controllers that have much better d-pads. The PS3 controller is popular for this reason, much better d-pad. Some people swear by the 360 analog stick, but I think such people are pretty rare. An analog stick has the problem of throw distance, where you have to move the stick a certain way in order to get the direction to read as "on". The game is based on digital inputs, so a digital input method is just going to work better.
2. The main issue: the face button/trigger configuration. Most gamepads have four face buttons. This game uses six buttons for standard attacks. There are some controllers that have six face buttons which people are fond of, like the Sega Saturn controller. Mad Catz also makes what they call "fightpads" which have two of the shoulder buttons moved over to the face for a six face button config instead, for exactly this purpose. These are much cheaper than a nice arcade stick, on par with a regular 360/PS3 controller I believe, and the 360 one has a much better d-pad than the stock controller obviously.
That having been said, some people find it awkward to do moves requiring multiple simultaneous button presses (throws, supers, tags, assists, etc) on a pad. Skullgirls in particular only ever requires a max of two buttons to be pressed at a time. There are no "all three punches/kicks" moves like the ultras in SF4, which helps when playing on a pad.
Then you have the
Hit Box which is basically like an arcade stick, except it replaces the stick with four buttons for up, down, left and right. Think of it like a keyboard with only the buttons you need, so you don't hit others accidentally, and they're all giant sized. These have become more popular in recent years, and some pros swear by them. It's also about as expensive as a good stick, so maybe not the best idea for beginners, but it's out there.