I’d say it depends on what you are willing to sacrifice.
Many people in here are die-hard Capcom fans, and they are so die-hard that they are so conservative of themselves that they can’t see anything compared to the Arcade.
I look at it this way.
SFA3 for the DreamCast has a hell of a lot much more add-ons and fightingmodes then the Arcade will ever have, more characters and even an intresting World Tour Mode where you will be able to fight against multiple enemies on the screen at the same time.
The DreamCast/PSX version of the game add new dimentions to it to the sacrifice of dropping the Arcade feel to it.
BUT, the PSX version is a bit different from the DC since due to the technical flaws the PSX had slowdowns, little space on CDs and among others.
The DreamCast uses GigaDiscs and has a boosted graphical preformance far better then the PSX and thereore there is more added to the DreamCast version of SFA3 then there is to the PSX version.
Secondly I do not think it’s an financial issue.
DreamCastgames are fairly cheap now thesedays due to the console itself being dead for over the past years.
You can find pretty much any game for the DreamCast for somewhere near 10 bucks each.
I saw MvC2 for $9.99 the other day and I bought Marvel Super Heroes for $5.
So its not like it’s your lifes biggest question ever.
But, I wouldn’t recommend you playing the game with the default controller in any way.
That one sucks completely for Capcom games in every way.
Buy a stick (if you can find one) or alternatively, buy a GamePad with a better button-layout (preferebly with 8 buttons) as a substitute until you find a stickfor a resonable price.
GamePads for the DC that have a better layout doesn’t cost more then 10-15 bucks.
In total, the DC version has some extra stuff that adds new dimentions to the gameplay and some fun stuff, but it sacrifices the Arcade perfection if that’s what you are looking for.
I myself am still stuck in World Tour Mode in that game and I can’t get past the last boss.
Gee. Wonder why?