Revolving backs are nice, but they make the camera much bigger and heavier (and in most cases more expensive). Best to stick to one that is reversible (you unlock it, rotate it 90 degrees, and re-attach it). I'll just re-iterate what's been said so far about pricing - you are unlikely to find a Sinar (even an F or A1) in useable condition with a lens for that price. Most of what you'll find complete with a lens and a few film holders will be press cameras and OLD monorails like the Calumet CC-4xx models (they made three, one normal - 16"-18" rail, one wide - 6"-8" rail with short bellows, and one long -24" rail IIRC) or the Graphic Views. Nothing at all wrong with them but they will be bulky because the rails neither extend nor collapse and they'll have few to no accessories beyond lensboards and maybe lens hoods. No matter what, your first camera will not be your last one because as others have said, you'll use it and find out some things work well for you and others you can't live with. But no big deal - there's plenty of other cameras out there. I don't know if there's a camera club in your area where someone else might already have a large format camera, but I'd try to find one and see if someone will let you borrow or at least handle theirs so you can get a feel for using a real one instead of reading a bunch of opinionated web posts.