Yeah the local resellers here haven't had that card in stock for months now, all sold out.
Most people buy the R4 3DS (not sure what one exactly, but the local seller I use only stocks reputable reliable and tested cards) now, it isn't expensive.
All my sister's kids have those cards for Lite, DSi, XL and 2DS.
Just for DS games obviously.
Edit:
This is the one they're using
Attachment 43664
Uses wood firmware.
Apparently the official name is R4i Gold 3DS, but also known as R4i DSN.
Sells for around $25 but you might be able to get it cheaper.
Compatibility
DS or Ds Lite: All Versions
Dsi or Dsi XL: 1.4.5 and everything below
2DS, 3DS or 3DS XL inc N3DS and N3DSXL: 9.4.0-22 and everything below