My advice on big printers is generally "you don't need a big printer".

Aside from big prints taking ages, and most people don't have the patience to put up with that, 3d printing (or at least fdm) loses practicality for mechanical parts above a certain size. For a small plastic part it might be plenty strong, for a big one it usually isnt. On a big print you've got so many more possible shear points (the layers) and the large size of the print makes it act like a big ol' lever for all the moment loads within the part. So a 10 N load on a small part and 10 N load on a large part are not the same. All of the big prints I've seen (I.e. Those you'd need a build volume like the cr-10) have been cosmetic and non structural, I reckon there is a reason for that.

For the record, my main printer right now has a build volume of 150x150x130 and I find it perfectly adequate. Occasionally I wish it was a bit bigger, but only by 10-20 mm.