In India, device & data are not linked. You buy device separately and data separately most of the time. Most of the users are on pre-paid plans. Whenever their plan expires, they recharge.
Starting cost for smart phones is around $50. You can get very decent devices for about $100. When you consider most people use it for Facebook, Whatsapp, YouTube, and basic games, the performance is more than sufficient.
Data plans are available for as low as 7 cents per day with a 1.5GB daily allowance. Yes, it is 1.5GB per day. You just recharge it once in three months for about $6. That is the rate on lowest cost network. It may raise to $7 or $8 per 3 months on other networks. You can also get 3 GB per day allowance for $5 per month.
No other country is going to come anywhere near these costs anytime soon.