Again, I suspect this falls under 'European thing' but nearly everybody I know texts to an extent. This includes my (retiree!) parents and first grader neighbour kids (toddler++) who I suspect text better than they write. It's not a replacement for talk (except in environments you can't talk). Think about it as more of a replacement for short emails rather than IM.

I believe you have misread something. The 4-5 RSD is the cost for 100KB (in US terms, a little over ~$1.3 for 1MB !). To add insult to injury, MTS's gprs/3g connections are notoriusly unreliable/slow, basically good for (small) emails but not much else. WIth most plans you get ~hundreds messages for free (or discount) before you start paying for SMSs at the rate you specified.

It's a vicious circle though - we have a very little % of smartphones (price sensitive market), so GPRS is not widely used (and 3G even less) so the providers have little incentive to upgrade data services which lowers demand for smartphones further, circle complete.

EDIT: Disclaimer: I'm not a MTS customer (but other local GSM providers do not differ significantly neither in price nor quality).