That particular dvd transfer of Highlander got ripped at several different review sites. I remember the movie being good, but supposedly it's one of the crappiest dvds available, hence the low price.
Bad Boys (with Sean Penn) was a great flick, but totally depressing. The same goes for Silent Fall (Liv Tyler, Linda Hamilton). Rent 'em, watch 'em, try to forget 'em.
If you're in a buying mood and don't have a problem stocking up on some great, cheesy classics, then I'd recommend:
Doc Hollywood (Totally sweet; good date movie)
Singles (Ditto)
Flash Gordon (Cheese with a capital "C"! & Queen did the soundtrack, dude!)
Ladyhawke (Michelle Pfeiffer was so purty in that one; great love story)
Pump Up The Volume (Christian Slater; great soundtrack)
Purple Rain (Another excellent soundtrack; unintentionally funny dialogue)
Sixteen Candles (classic)
Witches of Eastwick ("Have a Cherry..."

Traveller (Mark Wahlberg and Bill Paxton delivering one of my all-time favorite movie lines: "Hey, Do you got a little Irish in you? No? Do you want some?"

Sharkey's Machine (The villan in this movie still gives me nightmares! Bleargh!)
None of those are what I'd consider "must haves", but if you need a few dvds as gifts, or just want to round out your collection a bit, there are some decent titles to be had.