Of course you can, I have my Benq clocked to 87Hz via HDMI and I had also another Dell clocked via DisplayPort - not a problem. But of course it depends on a monitor. Standard brands are usually locked so you can go max. 75Hz.
Did you pay 25 euros fees for 72$ monitor? It's a bit much, isn't it ? Are you sure they didn't take a real price and ignored what seller said ?? We have 20% VAT here, but don't know if any import fees. I think there is none for this kind of electronics so I should pay 301$ + 20% at most...
In any case, how good is the monitor ? Are you satisfied with him ? Any dead pixel or uniformity problems ? I mean one part of the screen yellowish or so ? It was like that on AUO panels. Do you have any extensive backlight bleed or orange IPS glow ? thx.