"Is the sucker gonna crack on me?"
That's highly unlikely. Frankly, I get tired of dispelling the rumor of "cracking frames" on SIGs.
That problem appeared nearly twenty years ago in some P226s which had reliefs milled into the slide rails so they would shed dirt and fouling more effectively. The problem, which never rendered the pistols inoperative, was quickly fixed by re-design and SIG replaced the cracked frames.
Use a high quality grease like Tetra Lube on higher-stress areas like the slide rails and the breech block/hammer interface [where the slide cocks the pistol during recoil] and you should be problem-free.
You can tell what year the pistol was made by looking at the dustcover where the pistol has been proofed. You'll see a tiny two letter code; it corresponds to SIG's letter/year-mfd. index that you can access at:
http://www.easterncannon.com
If the letters are KA, for instance, the pistol was made in 1990. The code starts with A=0 and goes through K=9, skipping 'I' because it can be confused with '1'.
That's a particularly good price for a P220 of German mfr. [some think that finishing and QC are better on them] and you'll be getting an extremely accurate and dependable pistol for your money.
Beware, though...those things are addictive.