Yes, the stakes are constantly going up - Ukraine has failed to prevent war (it had at least 4 months to do something - starting with direct negotiations or outmaneuvering Putin by providing unconditional amnesty to separatists - just like it happened with Chechnya), has failed to solve it at the start - when the costs were low. So now, when the costs went over the top and Ukraine stays bold on its desire to ruin Russia - Russia has to justify the resources spent for this conflict, and the "justified" mark is constantly moving upwards towards total elimination of Ukraine as a state.

"Peace talks" now for Ukraine equals death (at least "political death") for everyone at the top - their actions have caused lots of losses, they've spent enormous amount of resources and credit costs without any real achievements. For Russia - it'll not look like a victory either as the initial political goals were not achieved and are as far as never before. Though I believe the real goals were by far not the ones declared - give a "magic kick" to industry by forcing outsiders run out and prepare for the next "modern" war. Yes - this conflict is simply a costly preparation to the next.