Here in the U.S., at least, Tmobile has plans where you pay less for a non-subsidized plan. 2 lines of unlimited talk/text/2GB 3G/4G with unlimited 2G data is only $100/month, so $50 per line for what is essentially unlimited everything, with my data getting throttled after the first 2GB, which I never pass anyways. The catch was I had to pay full price for our phones.
The subsizdized plan is $140/month, so i save $960 over the two years. My phones cost me $400(x2) instead of the $100(x2) they would have cost with that plan, so I spent an extra $600 up front to save $360 over two years. So I basically saved $15/month.
Furthermore, Tmobile lets you pay that off in interest free installments of $15/month after the $100 down, so its kinda subsidized anyways, with me simply paying a total of $130/month before taxes/fees instead of $140. Ill have 3 months of it only being $100/month before contract renewel time.