Honestly, I've not totalled it up,...
but if I were to guess, I'd say about $20k. Probably more if you consider my music and gear rooms are two rooms I added onto the house. Then, it might be approximated at $40k or above.
In gear alone, I might be looking at $10k-$20k, but that's an off the cuff estimate, only. E'thing I have is of reasonable cost, but it adds up fast: piano, drums, 20 guitars, many reel decks, mixers and Portastudios. I collect gear as well as the strategic gear purchased out of basic need, and I have way more gear than would be needed for an actual single or dual basic functional setup.
I'm not the average case.
I have e'thing from the Tascam MSR-24/M-520 to the MF-P01. If I really like a piece of gear, I usually buy two or more. I have half a dozen 244's, 3- 246's, half a dozen MX-80 mic pre's and PE-40 parametric EQ's. I have about 5- 234's. I have 2- 38's & 4- M30 mixers, as well as an M-312 & M-35. That's only scratching the surface, but I don't have time for a full gear list.
Okay, I'll admit I'm a total gearslut.