Comparing the specs between the 440 and the 445, there's only a 100mhz clock speed difference. Same cache, etc. So unless there's a major change in the revisions of the CPU itself that somehow makes it run more efficiently, I'd say it's an absolute waste. A small 100mhz increment is nothing that can't be fixed in 20 seconds by OC'ing it a tiny bit through the BIOS.
So unless you can find Benchmarks showing the 445 OC's a lot better, runs cooler, etc... I can't see any reason to spend a dime more for it.
If you're interested in spending any more money than the 440, I'd suggest using that money to buy a Quad Core instead of a Tri-Core. Then you'd at least be gaining something.