If you have just bought an sp 540 & are starting out, the thought of getting or needing another cutter to cut you lam prints is idiotic, You can print & cut a BOATLOAD of jobs before you need another cutter, especially if you are by yourself. The Roland cutters do a very nice job for the people who know how to set them up, I have one that cuts my lam prints so close it is just plain scary.
The SP is a very versatile machine that covers a wide variety of tasks for a small shop. There are more than a few shops out there that have made a lot of money with the machine you bought, do the cleanings & search the posts for tips & tricks, enjoy the printer....it's one of the good ones.