It's Horses For Courses
Some products like caps and coffee mugs have curved surfaces and therefore need a special design of heat press with a curved heat surface of the same or similar curvature.
The next question is in regard to the largest product and/or logo that you might need to heat press. Heat presses range in size from pocket (13cm x 13cm) right up to extra-large presses for full garment panels (80cm x 100cm).
Last but not least is the style and method of operation:
Clamshell presses
** Not good for thicker products because back of the press closes before the front
** Easier to accidentally touch the heated top bed when loading / unloading
Swing away presses
** Usualy much heavier than a clamshell
** Auto open models are more expensive and require an air compressor too.
The reasons are fairly straight forward. They are made in countries that have low labour costs and poor manufacturing standards as compared to Australia, Europe and America.