After having seen a fellow shooter use his 28 gauge (it was an over and under) to shoot sporting clays and five stand, I too would be led to recommend it over the .410 bore for any serious hunting endeavor. However, for strictly squirrel scattering, I myself have been fancying the smallest of the two in side by side configuration for a moment now. This idea has not left me -quite unfortunately, I must admit- but I have come to consider the 20 gauge side by side more of a realistic proposition in terms of usability, especially with regards to versatility and ammo choice ; I do not yet reload.
I must underline, for alien citizens like most on this forum to better understand such a dramatic change in my point of view, that our good government, in its infinite wisdom, has miserably failed last Spring to pass a bill finally allowing us to hunt the little tree rats. Apparently, some vegan tree huggers said it would be bad for the ecosystem to eliminate a few rodents which, if memory serves, were introduced in America by Europeans.
For myself, not quite in the same budget range as O.P., Yildiz shotguns are very appealing. I suspect them to be of adequate quality for the occasional walk in the forest on which they would accompany me, most likely for the rest of my life, and maybe even for my heir's.