How much is the running entrance fee in the month of January. We are thinking of a vacation affordable enough for a family of 9

Disney recently changed their pricing scheme and various by date with many many options ... price will depend on various choices you make ... date, lodging, single park per day vs hopper, #days, etc

Sorry, we were there in August.

There are several running events in January. All with varying costs. If I did this right, see this link: https://www.rundisney.com/events/disneyworld/disneyworld-marathon-weekend/

There are many variations for Disney. It price depends on length of vacation, if you are on or off property, if you have the park hopper or any other packages. If you are staying off property and plan to go to the park it is $109 per person, per day for everyone 3 and up.