I own a 505, I bought it years ago back when a 10-10 cost $39 and I thought that was too much money at the time. A quality scale well last a life time if you take care of it. Redding, Lyman, RCBS, and a few others all make quality scales. The 10-10 is the top of the line, nice to have but not necessary.
If something would happen to my 505 scale to render it useless,,,, now that the kids are gone, the house is paid for, the cars are paid for, and the dog passed on, Id buy a 10-10 without hesitation.