What were the (other) factors causing the collapse of the Soviet Union?

Lithuanians might claim their peaceful movement for independence. Some might claim even Catholic Church influence within Soviet Block (the pope was Polish). Other versions: slave’s desire to be a freeman; imperfection of planned economy comparing with market economy and others. All that fits but there is one particular point, without that it is impossible to succeed in any project. It is funding. When armaments drive reaches its most sophisticated level – Star Wars, your coffer must be (very) deep and renewable. This is not the same to fund and sustain all Developing countries and race in Star Wars program at the same time. For the economy that relies on the hard currency only from the oil export, developing both projects is gambling on your lucky star. But even (junior) high school student knows word diversification. For Soviets, theirs sole marketable product was oil. Though Soviet physician’s salary was hundredfold less than his Western counterpart, the crude extraction costs in Siberia weren’t even close to that comparison.
Conversely, it was much more expensive than in one particular country. The country, whose name wasn’t on the top threats list of the creators of Soviet empire, neither it was on the list of following rulers who could consider presumptive menace. Not sure if it was on the list at all. Less than five decades ago ruler of that state could place all his treasures on few donkeys. In the ninth decade of last century Saudis flooded the world with cheap oil that drove the world price of crude oil bellow the Soviet cost of production and transformation/delivery. That was the same as to disconnect the oxygen from the terminally ill patient. The giant Soviet system ran to the dead end with a stunning acceleration.

P.S. Dear fiends, amigos and amici, kamerater, and priatel, kumple, and prijatieli, copains, and venner,
we went ENGLISH! It’s the first try, therefore may be very odd for the person with a (very) profound English language. I will keep improving. Promise. I’m still youuung !?