for convention time as I am doing. After check in I always take out a few minutes of my trip and head to get some supplies, mostly bottled water, some fresh fruit, and anything I might have noticed I forgot.
I go to the Neighborhood Walmart store which is a while 1.4 miles away on E. Silverado Ranch Blvd. which is the same street as the SP parking garage. It's at 490 E. Silverado Ranch Blvd. that is a right onto the street from the SP. Takes about 3 1/2 minutes according to Google to get there. Saves me lots of money in bottled water which I drink a lot of out there. My wife also thinks off another few items she would rather buy and use out there instead of packing.
If you use Wells Bank and have an ATM there is also a Wells Bank a parking lot down on the same side from the Walmart above. I like to keep some money in here for the trip instead of getting travelers checks. Just my preference.

Just trying to make a dollar streeeeeetch a bit as then I have more money for the convention.

Also helpful to know where a store close by is if you need some supplies and not pay gift shop prices.

Don't forget to check out the give a ways or specials the SP has at its' food places, bars, and casino. Cafe has super specials from 12-6AM.