Breanna: yep, bootleg. the US version of the Sailormoon DVDs have been out of print for about 8 years, and were you to buy a legit one (off amazon, for example), it would prolly run you several hundreds of dollars. japan, to my knowledge, never put out a DVD box set for sailormoon. japanese DVDs typically have, at most, 2, maybe 3, episodes on each, and cost around $40 US (even more now that the yen is so whacky).
that said, this is one of the few times that a company did produce a sub only. ADV didn't have access to the old DIC dubs (remember, the ones that ran on TV? they were _awful_), so they released it sub only. but, there was only the 1 subtitle track in english, and the audio was terrible (mono only).
ALL US DVDs are Region 1 ONLY! ALL JAPANESE DVDs are Region 2 ONLY, and you cannot play them on most DVD players in the US. if you ever encounter a DVD that is all regions, or 0 regions, or region 9, then there's a 98% chance it's a bootleg.