no
I traded my DS in for a DSi and they made me pay $100 more for it so they give you about $70 for a DS and you only have to pay $100 plus tax.
3 to 4 dollars
I would say yes, depending on where your trading it at. The best place to trade at is Gamestop. The DSi XL costs at least 20$ more than the DSi, but at Gamestop you can just trade and not pay anything for those 2.
$70 That was only a limited time offer though.If you try now you would pay $120
About 30 percent of the original price.
Yes, you have to still pay 75$.
if it is dsi ware yes
You need to connect to the DSi store, and pay for them there. You can then download them to your DSi.
Amazon will pay up to $35 for the game and I'm not sure what Gamestop will pay
Gamestop will pay for your DS or DS lite towards a DSi, but they usually give very little... (I think £50 for a DS lite...) they have an offer now that ends may 31, 2009, where you can trade in your ds lite for a dsi and only have to pay 100 pounds.
Unless you loaned the DSi, there is no monthly charge after you bought the DSi.