Your list must have skirted some of the good games on the GBA or been very lucky in its picks. I am still seriously kicking myself for not backing up that old
https://web.archive.org/web/20081015031903/http://rothmans.joskeonline.com/supercardsite/ site that covered the failures of the supercard GBA compatibility but what little is on internet archive and maybe the changelogs for the firmwares can serve to illustrate how mediocre the GBA supercards were compared to basically everything else. This is as Supercard cheaped out on memory and the GBA needed fast memory which means it paid the price in compatibility, some of which was offset by the mountains of patches the devs of it made that may or may not conflict with translations and ROM hacks but nowhere near 100% and nobody is going back to make more today.
Not all good GBA flash carts are 100 Euros or equivalent. The heights in the likes of the EZFlash Omega DE and Everdrive might be at or above that depending upon what you get but there are far cheaper offerings available that will play essentially everything* just fine and have done for years, indeed as mentioned above then everything from the humblest firecard to the f2a to the m3 to the EZ 3 in 1 to the random things on
http://www.gameboy-advance.net/flash_card/compare.htm nobody likely remembers today will run anything they fit on the cart just fine with possibly a trip to GBATA
http://www.no-intro.org/tools.htm or equivalent and maybe another patch from the link below for the handful of exotic hardware and anti piracy laden games. I would not necessarily suggest any of those in that list over some of the things still available in shops or that were around to see the DS rise up but if push came to shove you could get it done where supercards will have failures. As far as I am concerned GBA slot Supercards are only really to be considered for the handful of DS homebrew that benefits from them (and now we have DSi and 3ds homebrew that can dump DS games and saves then that amounts to a handful of games that did not have the source code/active developer necessary to rebuild them when DLDI came on the scene). If you found one on the street then yeah you can use it to play at least a handful of some of the great games the GBA has at something more or less resembling playable recreation, I would not however suggest parting with more money than you would reach down a drain to get. When everything else is as it would be on the original hardware or better still then yeah I rank the GBA supercards as bad flash carts.
*my usual list of troublesome GBA games, and fixes
http://gbatemp.net/threads/buying-a-gba-flash-cart-in-2013.341203/page-18#post-4756995