just because you plan to have a computerized machine does not mean you will not still need lots of time at the machine- you stated you have arthritis- how long are you going to be able to hold onto those handlebars before your hands are killing you? or your shoulders/back?
a long arm customer base starts with one person- and grows- she likes the quilt you quilted-shows it off- someone else calls- you do hers, ect---it is not an instant - ok i'm in business---and quilting enough to cover any expenses-it takes time= and you might jump in and decide you hate it!
it would be better to start with that bailey- get good- show off- pick up some business here & there if you want to- and as your customer base grows you can upgrade to bigger/fancier more expensive machinery- instead of starting with the expensive- and finding out it's not for you.