Conceivable, but far from proven. An apparent employee of a major ISP+TV firm (username started with a "g") claimed that all company decisions were weighed against hurting TV profits. If neutrality could eventually force them to
decouple those decisions, prices could go down and performance up.
Further, ISPs are currently profitable by a hefty margin, so they could continue operating the same network at the same price, but neutrally WRT to content.
Actually, I can't think of any reason why net neutrality would ever cause prices to increase. All ISPs need to do is give customers a dedicated allotment of priority/low latency inbound and outbound traffic, with the rest of their "advertised speed" served as best effort. Then the customer can decide what matters to them (or the application designers for less technical customers), and that should be cheaper for ISPs since they need no DPI hardware and fewer employees deciding what to throttle for profit.
"Possible", in that it cannot be categorically ruled out over scenarios and timescales, sure.
But a lack of "net neutrality" isn't going to cause broadband providers to magically freeze their prices either. So it's a choice between a one time "possibly more expensive", and continual raising every time providers buy more advanced dpi gear, segment offerings into more proprietarily-priced "services", and slowly dismantle the end-to-end principle.