^^^The amount of money you should set aside for repair, added to the 1200, would exceed your original 1500 budget. Getting an extended warranty is always a crapshoot and there have been volumes written about the advisability of doing so, but no warranty at all is, imho, tempting fate.
I don't know how worried one should be about the caps issue on Samsung. Sometimes a mfg. will upgrade parts during a model run in response to an issue like this, I don't know of any way to find out if Samsung has done this with regard to the caps. I do know that their preferred repair method is to replace the entire power board, which costs upwards of $300 with a labor charge in the neighborhood of 100. One of my co-workers was lucky enough to have needed this repair while the factory warranty was still in effect and the tech let him see the "bill".
While the B750 is indeed a premium set you could easily get a very good high-midrange model at Costco, who doubles mfg. wty. Alternatively at this time of year one can often find such sets cheaper at normal retail stores than at Costco, but without the doubled wty. Something like a W or Z series Sony or one of the higher end Toshibas or LGs should fall into your price range about now.
