Yes youre getting something horribly wrong there mate. Renting off the market is pure rent, after renting for 2 years, you own absolutely nothing. After 2 years of flower running with me, you own the pi yourself.
In those 2 years, you would have lived in pi while flower running. Also in 2 years you would have paid 720m to 750m which is around 120m to 150m over the pi cost of 600m. Its the best bang for buck deal for pi there is.
Only the finest of smart arses cant see this.