Without me digging through my archives, I recall Bally's (The real Bally, Bally Manufacturing Corporation) IPO was $25,000,000.00 in the late '60's. Bally was already 37 years old but was private. They were making slot, flipper pinball, bingo pinball and arcade machines. The idea was to pay off the bank loans as the banks wanted out and some of the investors were forced to sell their interests due to legal issues.
Adjusting for inflation puts that at $167 mil. Figure 20% of that ($33.5M) was for the flipper pinball portion. This includes profiteering and stuff so $25M is a good reference point in today's dollars. Amazing how one of the smarter guys not long ago thought he could do it for way less Capital plus pre-orders. Fortunately he was able to get investors as public shares in pinball manufacturing won't make it these days.