Yes you can do it yourself but you will need a ck3 and Probe 3 to get your key from your drive again, cause untill then you won't be able to flash it. The hardware needed is going to cost you probably more than the 50€ (you will probably need usb pro too and power molex if your computer chipset isn't compatible with the flashing). But in the end it will be worth it if you need to flash more often.
And no it's not true that you can't save anymore on the banned xbox, you can even still update it too.
If you live by any chance in holland you can PM me. Can help you with the flashing if you do 't want to try yourself