Before..., the value of bitcoin is too low because the its limited supply is higher than demand but last year (2017) due to its popularity high demand comes in and the value of bitcoin increase 1300% of its value from the start of the year and that why bitcoin now is too expensive.

About affording a bitcoin a potential investor dont need afford 1 whole bitcoin, most of the people outside crypto world thinks that they cant invest on bitcoin because its too much expensive they dont know that they can invest even a $1, Almost everyone looks at its price first and if they cant afford the value of it their interest will suddenly lost. (like you see a new mobile phone released in the mall and you like it very much but you only have $500 in your pocket and the price of the phone is $1500 and you just leave..., but you did know that there is a installment process without interest). People sometimes afraid to ask.