Seeking advice on purchasing a Monza Calibre 36 CR5110

Hello, I want to buy this Tag Monza CR5110. I bid for it at an auction but I'm not sure If its worth it or not. There are some spots/impurities in the mechanism I can not make out if its corrosion or not. This would be the first vintage watch that I buy, I'm not familiar with repairs reconditioning and the costs of it. If it is corrosion how warried should I be, can it be cleaned? It has no papers ad the strap is not original the final price is 2200 euros. Can any one help me with some advice on this issue? Thank you in advance!
Ref nr: CR5110
Serie nr: 178740