https://3ds.guide/get-started-(old-3ds)
System Transfers will work in the following directions only:
New 3DS or New 2DS -> New 3DS or New 2DS
Old 3DS or Old 2DS -> Old 3DS or Old 2DS
Old 3DS or Old 2DS -> New 3DS or New 2DS
the games for DSiWareHax are about 1.99 - 4.99 so its cheap. But if you cant buy (new or used 2DS) or borrow a 2nd system then you have to buy a card.
Whats the price for those cards ?
Sure but NtrBootHax is not a working method right now so there is only DSiware or Hardmod.
I borrowed my sisters O3DSXL (it was still Stock 4.5 =P) installed CFW on it. Bought Sudoku game in eShop for 1.99€ and done.
So he can wait, probably month, for NtrBootHax or get another...