Corel 10 vs. Illustrator advice

 I am working in CorelDraw 10 and I have to send lots of files to printers and other designers that work in the Adobe world (CreativeSuites Illustrator and InDesign). I have Illustrator 7 and have finally figured out a setup that works for both but am running into problems with sending and receiving files that aren't saved low enough from the CS or they need higher versions.

My questions is does anyone recommend a higher version of CorelDRAW and/or a higher version of Illustrator. (without breaking the bank!)

The art I work with can be anything from simple pages of icons to layouts of 16 month calendar spreads and everything in-between.

Thanks!