When I first came back to the disboards a little over a month ago, and waltzed on over the budget boards, I thought that saving 5% on Disney GCs was the best that I could do. Wow, did I learn I was wrong!
I've now acquired enough GCs for our trip (which is less than $5k, but more than $1k) using a variety of means that have saved 10-15+% on the cards, but that has only been through using a variety of payment methods and special deals, and has been somewhat time consuming (though I have enjoyed it, so that doesn't bother me). If your priority is knocking out the MSR right away, then that is probably worth it. If you'll make the MSR some other way, and your priority is to save money at Disney, then probably not. Just my opinion.