While most Jukis are higher priced, they do have two or three computerized machines (with fancy stitches) for around $700. Juki makes more industrial sewing machines than any other company in the world. Their machines are made to last and are very solid. I'd recommend you look at the HZL-F300 - it comes with a lot of features and accessories and is under $700.
I have a Juki HZL-DX7, which was about twice your budget. I have used it almost every day for a year and a half and it hasn't given me any grief. It can sew through heavy denim easily - I made two bags for my husband's games and it breezed through multiple layers of the denim without complaining. I did change to a 16 needle for that sewing.
Mostly I am piecing quilt tops, which is easy for the Juki. I put in 4-6 hours a day on this machine and it doesn't complain - though I did bend a part on my bobbin casing recently and had to replace it. I do have to clean lint out regularly, but most Jukis have sealed bearing so you don't have to oil them the way most machines need to be oiled regularly.
There are two lines of home Jukis - the computerized with fancy stitches and the mechanical that only stitch straight. For garment sewing you'd probably want a computerized machine so you'd have overcast, zig zag and other stitches to finish you seams.
Juki Junkies on YouTube has some good videos on various Juki models. They also have a shop (in Brandon, Florida) where they sell them, but you are better off finding a shop near you.
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