Discount price on 1 year plan?

Code: Autumn20 for a 20% discount the entire shop.

Wonder if it applies to the SIM plans. So $150 minus 20% = $120 and you get 5GB AT&T LTE a month for a year.

Nope. There's a notice right under the banner discount code offer stating that preloaded SIMs aren't eligible. (The first time I saw one of these store-wide discounts, it would permit the discount on the SIM.)
I think the site-wide Ebay discounts have worked with the pre-loaded SIM-- and buying from a 3rd party is maybe smarter, since FP will never have your credit card or address via that route, unless you want them to.

Darn, btw, I checked Amazon... the biggest plan they have is the $50 for 1gb/mo... nowadays, I guess I gotta have at least 3gb to be safe from overages, so looking at 5gb plans.

Well, they have the 5gb plan on BestBuy, so I guess I could also do Shopkick for some credits and also discounted gift cards to get a slight discount for my out of pocket portion.