In a similar vein, is there a cost effective way to purchase a single ipv4 address? Just for the novelty I think it'd be cool if I could spend ~$100 to have an ipv4 address that's permanently mine.
The minimum IPv4 allocation is a /24 because that is the smallest network that can be globally routed. Smaller networks are filtered out of BGP to stop routing tables getting too big too fast. Anything smaller than /24 has to be rented from a network provider who will advertise an aggregate route covering many customers.