Setting aside for now the ridiculousness of 10k for one month of travel and taking out a loan for it...

If you are alloting 6k for tours which include food and accomodations and 1.5k for a hostel + food in Amsterdam, what exactly is the 2k spending money for? You say drinks, but if you are going to be spending 2k on drinks in one month- let's average a drink to be $5- that is 13 drinks a day for one month! I doubt you will be able to enjoy much of your trip if you drink that much. Even if half of that 2k budget is for the 'extras' - that is 6.5 drinks per day for a whole month. 6 drinks a day here and there isn't bad but on a holiday I can't imagine keeping that up when you are on the move and sleeping in different places every night. I know you are going to Russia where Vodka is pretty standard, but you probably will be offered plenty of Vodka unless you are just really a top shelf kind of person.

I'm not sure what your 'extras' are. Besides food/drink/accommodations/tours which you have already budgeted for, this means souvenirs or emergency contingencies. I guess you just have expensive taste because I can't imagine spending that much on souvenirs unless you are specifically going to be buying high price items like rugs, fine art, wines or imported cheeses.

Now back to the whole trip plan- if you are going to be able to pay off the 2k immediately, why not just take a trip that is 2k or less? You can easily have an enjoyable trip in these places for 2k for a month.

Like others have said, the expensive tours will be full of older people who have the luxury of spending their earned money or retirees. Regular tours are full of people of all ages but they do not cost thousands of dollars.