A nice 7711 with the 3.9 liter long stroke engine and only 1500 hrs, goes for at least 7000 Euro here. Lots of them go back to Eastern Europe, as everyone wants them because of their low running cost. Parts, original as well as aftermarket, are available in great numbers and cheap (there were made over a million of this UR1 series since 1960)
Over here, these tractors depreciate about 50% in 20 years... We did have a different monetary inflation rate, so reckon thats roughly the same as the depreciation of a Deere in your part of the world.
The 8000 dollar, is about 5334 euro at the current rate. compared to what they go for in europe, its a steal.
Your dealer will allways be able to help you out if you need consumable parts like filters, off shelf. If you dont want to spend too much, you can get them from ridgeway enterprises, who imports original parts for 2/3 of the price:
Zetor Tractor Parts