Bps and bps have different units. We usually say that the download speed is in bytes, while the transmission rate is in bits, and 8 bits is equal to 1 byte. So you have to multiply it by 1/8 to get your actual bandwidth.
Pulling optical fiber is much more expensive than pulling telephone line because the technology and equipment are different. Telephone lines only need a cat and then set up at the local office, while optical fiber needs more expensive equipment and money, which is not cost-effective.