i have an epi goth thunderbird and one time i decided to take it to school for the hell of it, but i don't have a gig bag. i borrowed the one that my dad uses for his j-bass, but the headstock was too big and partially sticking out...is there any case out there besides the hardshell that epiphone sells (not spending 90 on a case) that works?
There are a few gig bags that will fit Thunder Birds, but not many due to weird body shape and head stock. Go to your local music store and try out some bags. One is bound to fit. You can also buy the Gibson gig-bag if they still sell it. I own a Gibson Thunderbird Vintage IV and it came with a Gibson gig-bag and hardshell case, but I don't use either cases any more. The bass lives its life inside an Anvil flight case when its away from home, just like any other bass I own.
I'd highly recommend a hard case over a soft case. 90$ ain't bad for something that'll keep your bass safe.
I recommend to not get gig bags. The only time I would ever use a gig bag if I had one, would be if it was raining. That's it. Hard cases are the way to go. Or just not use one at all.