Over the years, between Transformers, Gundam, and Macross, its been well over 4 or maybe even 5 grand. In one shot, though.... oh, I dropped $600 on 2 Super/Strike Stealth VF-1Js plus other stuff. Thank goodness I got out of those expensive hobbies, lol. Now it just comics and I usually keep that under $50 per month...
I weightlift and damaged my knee, it was livable with if I didn't bother about doing heavy weights but I had it fixed so I could resume with heavy weights at the hefty price of £4000!
Bought a motorbike recently but im sure the car guys top it easy. Most ex tf was a loose fm for 350. A boxed overlord was abt there too.
I'm just about to pass $31K in TFs once my POL gets here in a few days. Other than that, I spent $4K on a new Ninja 250 motorcycle, then proceeded to spend $1500 on protective gear and another $2K on mods for it. I think there may be one or two more things I could do to the bike, but I am happy with it as is right now. I freaking love my bike. I also just spent $1000 on new martial arts weapons for me personally, in addition to the $500ish that I spent previously. That is less a hobby and more my profession though, but I still enjoy it (picture is of the weapons rack that I have at my karate school).
$32,000 and some change. Once I can convince my wife to drop let me money on a new paintjob add another 10-12 grand though.
I bought and sold Arcade games / PCB's I worked for Sega / SNK / Capcom / Taito during the heyday of Arcade games in the late 90's / early 2000's. Seriously the most expensive hobby in the world.