Should I upgrade amp?

My system is very entry level: vintage integrated Marantz 1060B / wharfedale diamond 10.1/ musical fidelity vdac MKII / denon dp-300f with ortofon 2M red cartridge.

It sounds good to me but wondering how much improvement a more modern integrated amp would make. The marantz has been cleaned and gone over by local shop. Not looking to spend over $800 or so (preferably less with good used deal). Listen mostly to streaming MOG and some vinyl. Not a large room. Any thoughts/advice on whether int. amp upgrade in this price range will make much improvement and if so suggestions? Thanks

+That amp is sweet and smooth, but lightweight, and lacking at the top and bottom extremes. A better integrated would certainly provide more extension as well as visceral inmpact. A used exposure would be nice if the price was right. There are plenty of others.
I've found a variety of NAD BEE series integrated amplfiers to work very well at your price point. The Peachtree Nova is also good if the Whatfdales are 8 ohm speakers. The Marantz is nice but you might get a bit more musicality from these two brands.