I purchased a midarm (BabyLock Tiara) off of Craig's List a number of years ago and it has been wonderful. I used it the first few years as a sitdown but soon found that my shoulders didn't like handling all that fabric. I researched and discovered that I could put it on a long arm frame...the Grace Q Zone Queen with extended handles and carriage and now I have a long arm. It's not as much space as a "real" long arm...about 14", but it works for me. I can usually do 2 rows before I have to roll it.
So, here is my advice....
-look at used...These machines are work horses and can go for millions and millions of stitches. Mine had only 500 000 stitches on it and came with everything plus she threw in a bunch of rulers and I paid $2500.00 USD. (I drove from Canada and brought it back across the border.)
- if it has a stitch regulator look very carefully at how it works to decide if you need it. The older ones were more of a pain than anything. I sold mine. Maybe the newer ones are wonderful?
- look into a suspension system - you can make one cheaply...I can tell you how I did it if you're interested...but it will save you a lot of hauling fabric around the table top.
-immediately look up Jamie Wallen's videos on Oiling Your Long Arm and Tension on Your Long Arm. You can thank me later.
-get the LED lights that are on a tape and stick along the throat of your machine above your work area. They make a huge difference.
- if you do decide to go straight to a long arm, try one first if you never have. Take some classes to get a feel for them before you go looking at them. This will help you know what to ask.
- if I were to buy a "real" long arm I would buy Handi Quilter (They make the Tiara), just because I've had such amazing luck with my Tiara plus we have dealers in the area, which I think is important.
Hope this was helpful. Any specific questions, let me know!
Watson