Accurized Mini-14
I've personally owned a sub-moa accurized Mini-14, and I can tell you from personal experience it isn't worth it. When you're dealing with barrels and actions of this caliber, you cant dump mags or you'll ruin your bbl. You have to clean it every 5 to 10 rounds and only shoot a round ever 2 mins or so. Otherwise you run the risk of ruining the temper of the steel. The .223/556 round reaches about 1600 degrees F and the match rounds get even hotter. Granted this is just a 'flash' burn, but when dealt with in rapid succession the heat will linger for a LONG time. This is why your SMG barrels wear out fairly quickly. The constant heat ruins the steel's temper.
You can shoot the accurized mini a lot if you want to, but over time you'll wear out your gun a LOT faster...
$300.00 for a decent condition Mini is a great deal! Take it regardless! Ruger makes some of the finest firearms in the known world! The above Ac556is the exception not the rule. I dont doubt the fact that the receiver cracked as he has said it did because noone's perfect and even Toyota makes lemons (I know... I had a 2004 Corolla S that was one, but I still drive them religiously) Its inevitable that you will find at least one bad apple in your bushel.
I would take the Mini and drop it in the stock, and then get on eBay and get the AN/PVS-14 thats on there, then a M4-1000 or M4-2000 suppressor from AAC. Then sit back and slowly collect the genuine ruger 30 rnd mags (the Ac556 and Mini's are notorious for not liking aftermarket mags... mine HATED them, but ran flawlessly on the factory mags...
Just a two cents worth, but IMHO you would do a LOT better and be a LOT happier with a tactical mini vise a accurized one. What would you need a sub-moa tactical rifle for anyway? Varmint? If thats the case get an AR platform so you can switch uppers from one used for ammo dumping and the other for tack-driving.