We have 2 XLs and we could not be happier! The larger screen is great! The 3DS is not that great for little one's eyes. As far as new games only being made for the 3DS, that is incorrect. While there are many games coming out this holiday season for the 3DS, there are SEVERAL new games for DS and DSi. I know this because my kids have a long list of games they want for their birthdays/Christmas.

I kinda want a 3DS just to play the new Super Mario Land game, but the screen is terrible to look at and I have perfect vision. Of course, everyone is different, but my kids have played all of the systems and they prefer their XLs hands down. We are waiting for the new Wii U to come out. That will be the next major thing we get as far as game systems go.
As far as deals go, you might check GameStop. They sometimes sell refurbished units for a great price. They are very reputable and I believe they guarantee their stuff. We get used games there often (for multiple brands of game systems). We've never had any problems at all. Good luck with your decision!