Absolutely without question one turntable with two arms. As you said at the same investment level. Turn table performance improves phenomenally with cost (assuming yo are doing your research). Two tts at half the price at almost any cost level are not going to sound as good.
And phonostages even more so! Until I reached the ~ $8K level every Phonostage hindered the output my turntable. It is really easy to get a TT that exceeds the capability of your phono stage.
I have been listening to turntables for well over fifty years. And began my pursuit (very inexpensively at first) of the high end over 40 years ago. I am sure I have owned nearly a dozen highly rated phono stages of all cost levels and until I bought my first Audio Research Phono stage 30 years ago, they were of different brands.