Yes, especially if you are thinking that you might be applying to MD programs. When I was at PCOM, the school paid for the COMLEX and I got the military to reimburse me for the USMLE. The military will reimburse one test but not both, but even if you have to pay for one, it is money well spent.
With this in mind, it is really hard for DO students to match in MD Ortho programs. However, taking the USMLE and doing well will give you more options. If you change your mind and want to EMed, Anesth, Rads, Optho, etc and choose to apply to MD programs, most wont even look at you without the USMLE.
Just my experience and my 2 cents