There are great used machines that are quite affordable. As people upgrade they turn in machines all the time. if you have a Sew and Vac in your area check them out . Many will give a warrenty on a used machine. The all mechanical machines are much easier to maintain than many of the computerized machines and will last and last . Just a note light weight is not always a good thing ... it means many of the metal parts have been replaced with plastic.
But think about what your REAL needs are before and write them down .. it is very easy to get "up sold" .