As a guitarist with 4 guitars and a bass, I can tell you that you can do a lot with a little. Using amp sims, I have access to more guitar amp sounds than I ever imagined. For a decade I did 90% of my synth sounds with a single synthesizer. An Ensoniq TS-10.
But back then, my music was still mostly guitar based. Synths were an add-on, like the Prophet 5 parts in Talking Heads songs. Now, that ratio is flipped. I have 9 hardware synths (though one is for sale) and about 150 software synths, though I don’t regularly use most of them. Some of this is more like being a collector than anything else.
So, there’s no answer that you can get from someone here. My advice is to start slowly and consider each purchase. If all you are after is adding the equivalent of the Talking Heads Prophet 5 type sounds, you could get away with Repro and be done. If you’re looking to explore and experiment… still start with something like Repro, and then when you find yourself unable to make a sound that you want with it, start researching your next purchase.