Ok my friends thank you all for your input. So I did it last night and I managed to finally get my Goram. I instantly used all 50 burgers I saved up for him, and something like 300 mozzarella cheese on top of that to get him up to the level I'm at (84) and I even had some mozzarella left over to buff some of my other heroes to level 84 as well. Now begins the audacious task of upgrading his abilities which take me a good couple of days before I can unleash the beast into my deck alongside Malrath, Nilya, Sylphi and Firehawk. Elric gets relegated to the reserves
In the pulling process, I was also able to get a lot of Jasmine's soulstones, meaning next time she is in the shop, I will summon her too - I only need 3 more. So I've pretty much got all I asked for. Plus an additional 2 heroes who I didn't have in my team. Now I'm back down to 1500 diamonds though, so while this cost me a lot, it was well worth it.
Vulko is my next target, however it depends on whether or not the Jade event continues to return or not. I also think it will still be a few months before they release her though - and so the diamond saving process begins again