The RX550 is quite a bit faster than the GT1030. Even the older GTX 750ti is faster. Find a used 750ti and you'd be good to go. Part of the problem is that the GT1030 is made to fit in a 30w power envelope, while the other cards like the 750ti and the RX550 push up to 60w. This of course allows a much higher performance envelope.
All things being equal (ie: price) - the pecking order is: RX550 (1), GTX750ti (2), GT730 (3)