Your thinking is a lot like mine. Get the gun for 500, fix it up for 500. There is a place near me that has older models new in the box for the same prices as they went for new maybe 10 years ago.
I like the rugers, cause they are so much like the M1A, M14, and garand. Very reliable, very easy to maintain and take apart. Also, look way more 'normal' to the sheeple.
The mini30 sounds like a good bet, due to your ammo situation.
One of the reason I have not minified myself again, yet, is due to the new availability of different ammo. I was contemplating our mini's being in the new 6.8 military round. The stainless mini's are available as such. A stainless mini with a wooden stock would still be lowe profile than my AR, and the word on the street is that the 6.8 hits with a lot of authority, at close range.
I am just not sure if I want to invest in another cartridge, when the M1A is my 'main' rifle, and the .40 P40 my main recreational carbine. I have a ton of .40 laying around, and the P40 came with 3 mags, so I havn't had to spend any money on it, other thasn the initial purchase price.