As to the question on the vibratory rollers I would say from experience that smooth drum soil compactors will now days all have the vibrate function. The rollers themselves don't have much weight so to achieve deep compaction the vibrate function is necessary. The rollers used to be rated by amplitude, which is how hard the machine pounds the ground, and frequency, which is how fast the machine vibrates. The usual type has a single frequency but I have seen multiple frequency and variable frequency units.
The value of your iron is dependant on where it is located for the most part. I didn't see where this auction was located but if I look at the iron in relation to auctions in the United States the roller would not bring much money at all. It would be a gray market unit that is not popular and has little if no support by an established dealer network. Parts to repair it might not exist in this country. A knowledgeable buyer in the states might risk as much as $7,500 on it in an auction if it is fully operational. A dealer working a trade would politely decline to consider it at all.
The skidsteer market in the United States right now is absolutely flooded with mulitple manufacturers and far too many machines. I view that market as about the same as cattle with out the benefit of meat, they are almost a comodity now. I could find many used skid steers on dealer lots for $15,000 knowing they would accept less. You could probably cut that figure in half and work up or down some when you go to the auctions.
I have been hearing that there is a big market going on now in the middle east for parts machines and older used iron. Those markets may currently bring higher selling prices. At any rate the primary way any machine makes money is through using it. What you paid for yours will make little difference if you get enough use out of each to make a profit.
Good Luck!