i agree. i have a GBA AGS-101 with an everdrive. does all my needs for GBA games.
you dont need to get everdrive could be another flashcart.
I have the Everdrive in one of my GBA's, but I just recently bought the EZFlash Omega to use as my daily driver. The save states are what won me over and to be honest, having used it for a while now, it's the one I'd recommend for price and features.
Don't get me wrong, I like Krikzz's stuff, I have just about everything he's made. But until he releases the Everdrive-GBA X7, the Omega is the one for me and if you're looking to save a few bucks after shelling out for a good GBA, the Omega will see you right.
Incidentally, another option of course is to buy a DS Lite, you can use GBA cards/flashcards on it and the screen is awesome. Alternatively you can make, or buy, a Gameboy "Macro". Which is just a DS Lite with the top section removed. I have one of those too, they're pretty decent to be honest and you can pick them up really cheaply. Plus you can also use the DS slot for a flashcard and run some emulators (so long as they don't need the top screen.)
Everything is better than a K-101. I had one and disposed of it pretty rapidly.