Jared,
I make my own grunt guts, but also buy them, for me it is a time issue and a financial issue, if someone wants my custom wooden guts, I charge more for them, due to the fact that you have much more time and equipment usage, IE, bandsaw blades, drill bits, Etc. IMO, Buy the guts, and do not think twice about it, there is not a history behind the grunt calls like there is on duck calls for one thing, and for another there are other variables as with every call than the toneboard, tuning and internal variations are just as or even more important.
I do have different feelings when it comes to duck calls, but I also feel do what you are capable of for now, and learn and ENJOY yourself along the way. I have a family so I hate to admit this, but most nights I go to bed thinking about calls of some kind, and I wake up each morning thinking of calls. Whatever you do, do it for yourself!!!!!!!!! And ENJOY whatever you do !!!!!!!!!!!!!!!!
Good Huntin and Call Makin....................Ken