While the box sets of Will and Grace are pretty affordable, you should probably know that the episodes on them are the edits used for the show in syndication. Sometimes there are pretty obvious jumps and gaps where they cut out the original jokes or plot points.
For example, in the episode "Dolls and Dolls" (guest starring Madonna), Will leaves Grace and Jack in the apartment in search for more medication, but after the scene with Madonna and Karen in the bar, Will's shown searching the apartment for drugs. In the original broadcast version, Will stumbles into the bar and bumps into Madonna and Karen, leaving when Grace and Jack arrive on the trail of Will.
I recommend trawling through the internet to download the original shows if you're a fan of the original shows.