My commuter/errand bike is irreplaceable. It's a Bridgestone XO-2, 1993 model. Only 1500 were made, and I ride a 52cm, so they're rarer than Sasquatch riding a unicorn. I lock it up with a u-lock and a cable, and hope for the best. If it gets stolen, I'll be upset. Well, more than upset---I'll be livid. But if the choices are ride a POS or ride a bike you like, I'd say go to the bike you like. There are LIMITS, however. I have another bike that cost a whole lot more than the Bridgestone,and it's too flashy to risk locking up. Even though I could get another one just like it, the financial hit for losing that one would be too severe to risk.
I suppose it depends how much of a financial hit the grand would be to you if it got stolen. If you want to risk it, and the benefit is worth the risk, then buy your thousand dollar ideal commuter, lock it properly, put Pitlock skewers on the wheels, and go for it.