I used to work at an ISP and when we upgraded an area or were able to offer higher speeds people were interested right up till they found out they'd have to pay more, then the interest disappeared or they were outraged that it would be even more expensive.

I'm in a similar situation now, I can get gigabit FTTH for £100 a month but tbh I'm perfectly happy with my £29.99 a month 80/20 FTTC as it's more than enough for me and means I don't have to rewire the house or have any more kit installed until they eventually switch off the copper network and force my hand.