When looking to purchase an embroidery machine, first determine how you will use it. Will you be creating one-of-a-kind items for personal use, or mass producing items for sale?  Do you plan to do a lot of embroidery or just add an initial to a blouse or monogram linens? For business use, you may wish to purchase an industrial machine rather than one for home use. These are all considerations when purchasing a machine.

Once you have decided upon the purchase of a machine for home use, you'll have some features to consider.  One of these is the design or sewing area.  Most embroidery machines on the market today will embroider up to a 4-inch by 4-inch design, but many will embroider 5x7 or even larger areas. (Considering the design area of a 4x4 machine is only 16 sq. in, but a 5x7 embroidery area is really up to 35 sq. inches, and you might decide to opt for a slightly more expensive machine.) There are also many memory cards (like a floppy disk, but in a format that embroidery machines can read) available for 4x4 machines. These cards can run up to $90. However, many free or low cost designs are available on embroidery websites, but you will also have to purchase a reader/writer unit to be able to download these designs to a blank memory card that can fit your machine.  Some of the more advanced models (and also more expensive models!) can interface with the computer and take designs directly from the website without the need to create a memory card. 

Manufacturers such as Brother, Bernina, Babylock, Viking and Singer have information as to the specifications for each individual machine.  You should always check out their websites for the particular information you need on each machine.  It is also possible to submit a question to many of these companies about discontinued machines that you may find used on e-bay.  Hopefully this will shed some light on your search for the right embroidery machine for you.