As an Artesian Spas dealer, and because you asked about the Garden Series, you can find a better option in the South Seas series that will fit w/in your desired price range. The 735/748 are good options, have dual pumps and carry a full 3 year warranty on parts/labor.
The Garden Series is indeed their most basic units. They are not bad for the minimal amount of features they offer. And another poster was right: 220v isn't that bad for what you're paying for (their acrylic spas that usually run cheaper than roto-mold units). But again- The South Seas series is something you should investigate if you're staying in the $4-6k range.
I haven't had many problems with them, I get great support from Artesian Spas, and they use Balboa controls and motors. As long as your local dealer is also reputable (and that is very important), I'd say your better value is the South Seas line.
I hope this helps. Good luck moving forward.