I think with a bit of fucking about I can get a sound that I like out of pretty much any guitar/amp combo, but it's utterly subjective and YMMV
Within limits, I agree. The player is easily the biggest part of this equation, IMO - Jeff Beck could make a Squier Strat and
a Marshall MG10 combo sound magical.
Past that, I think guitars and amps are important for different reasons. Purely for tone, the amp is probably the most important part of the link, since it plays such a large part in "coloring" the sound your guitar produces. Huge, in fact.
However, I think the
way I play is largely dictated by the guitar. Things like neck thickness, body contour, fretwire, setup, natural resonance, and overall "comfort" of a guitar... If I'm playing a guitar that really gels with me, then I think I sound like a better player than if it's a guitar that I'm just not comfortable on. It's less a tone thing than performance.
So, as long as your guitars "fit" you well, then I'd worry about finding an amp that makes you happy. But, if you can go into a shop, pick up a more expensive guitar, and immediately feel so much more at home on it, then grab a guitar. I can sit down with my Strat, unplugged, and have a blast playing it. If you can't say the same, then the greatest amp in the world won't change the enjoyment you get out of your rig. Your tone, sure, but not your enjoyment playing.