I think this might be a stealth bump weekend. I just got the "You Have X Items Worth $X in Credit!" email from Gamestop. One of the games on my list is New Super Mario Bros U Delux and it states that the pro trade credit value is $33 so that would mean that the switch games showing $30 base is correct.
Just got the same e-mail and it included a link to the new 'Most Wanted Trades' list: