Yes, something is up with the watch and needs examining. Perhaps the watch has several problems?
As for repair / service cost; to do a throughout proper service, from a total strip to fully re-assembled takes me about 4-5 hrs, this includes pegging of all the jewels, demagnetizing every single part, etc etc etc. Next to that one uses expensive lubrication and cleaning fluids, no replacement parts included. Even with very low hourly wages of say US$10 for a skilled service that quickly exceed the price of a new Vostok. Never mind the extreme Western, or rather here in the EU, postage cost for sending forwards & backwards, which comes on top of the service cost.
I for sure can't compete with for example Ukrainian watch-repairers and always wonder how they do it? I do not even attempt. For me it would be purely labor of love. Also never mind if on top of these low wages, thanks to computerization and open financial institutions, the taxman knocks on the door ......
It also gets to show how extremely cheap these Vostoks are. You get a lot of bang for your buck, unparalleled compared to any other brand !
On the positive side; go to the WRT-forum and learn how watch repair is done. You have a nice casualty in your hands and an unique opportunity to learn a wonderful new hobby
Success with deciding what to do next