pizzaface18 "if gets to $1-$5"
https://www.reddit.com/r/Bitcoin/comments/4qws09/fee_development_this_year/d4wro9q

CubicEarth "some would be happy with $20"
https://www.reddit.com/r/Bitcoin/comments/4qws09/fee_development_this_year/d4x1mbl

paperno "according to Core tx fee of ~$10"
https://www.reddit.com/r/btc/comments/4au7l1/lightning_network_is_not_a_scaling_solution_for/

Jihan Wu "Core says: assuming 1000 LN tx per 1 blockchain tx, fees 30 RMB (100x increase)"
https://np.reddit.com/r/BitcoinMarkets/comments/48kf18/daily_discussion_wednesday_march_02_2016/d0krl0w

jratcliff63367 "when an on-chain tx fee is $5 the average tx will be $10k"
https://www.reddit.com/r/btc/comments/4au7l1/lightning_network_is_not_a_scaling_solution_for/d13w1h6

chinawat "if fees are $5"
https://www.reddit.com/r/btc/comments/4u2tk9/buying_anything_below_2_usd_online_with_bitcoin/d5n503b

thorjag "$5/$20 for opening/closing lightning channels"
https://www.reddit.com/r/Bitcoin/comments/3jbtmd/to_maintain_current_economic_expenditure_on/cunygsm