depends on price. If you can buy a similar boat without the problem for a similar price then is not worth it. Also depends on how extensive the rot is and how easily accesible the area of rot is.
Deck recoring is not really a big deal. Is messy and time consuming but if on a flat surface is really similar to performing a drywall repair. You cut out the rotted area and some of the good wood surrounding to get it all. Then you chisel it down to lower laminate and place in a couple of layers of cloth and matt and saturate with resin. Cover with the new core material and then build up on top with cloth, matt & resin and then fairing compound followed by gelcoat or
paint.
If the above description sounds like a project you would enjoy then go for it. If you do not like doing that sort of work then stay far far away. I have recored chainplate area and entire cockpit floor of my boat and have rebuilt the deck on a laser sailboat as well as repairing/repainting an 8 foot dingy. These are all small projects but will result is a real mess if not completed in a timely manner and properly.
One further note. If you are buying a boat with a cored deck and it has never had any section recored then it probably should have and has sections that require it. I do not know of many older boats that do not have some moisture in the decks.
Mike
Full Tilt 2