The Oceanic VEO 180nx was introduced in 2002 and has been out of production for at least 5 years. (Thus the great price on discontinued units still for sale on the web.) At the time it was Oceanic's entry-level basic feature dive computer that worked with both air and nitrox. As noted previously it only supported a single arguably liberal algorithm. If you buy one you should probably change the battery ASAP since these computers have been sitting on the shelf for years. The equivalent one-button model today is the VEO 1.0, which supports DSAT or Pelagic Z+ algorithms. My wife and I have both been using VEO 1.0 computers for the past 5 years and have no complaints. Others have complained about awkwardness of one-button operation but we like it.
I respectfully disagree with the opinion that a compass isn't needed for diving on Bonaire. Will you get lost without one? No. But having a compass makes it easier to dive immediately from your entry point and return to the same place at the end of the dive without surface swimming and/or repeated prairie dogging to get your bearings. For some sites (like Bari Reef, Something Special, or the Cliff etc.) a compass probably isn't needed. But it sure makes diving easier at the southern sites where there's a significant distance from shore to the drop-off. I can't help but shake my head at all of the divers I see swimming on the surface to the mooring pins at the drop-off because they can't find it diving without a compass. They're missing out on 1/3 of the dive by swimming over the shallow sections.
Arsalan please forgive me for putting on my instructor hat for a minute, I hear a few internal warning bells going off. While you profess desire to increase your safety margin by using a dive computer I'm concerned that you appear unfamiliar with how to use the device to actually increase your safety. You've mentioned willingness to make deco stops and state intention to "plan my dives accordingly and not rely on the dive computer to do the planning for me." Deco stops are generally discouraged in recreational diving for safety reasons. And how else can you plan your dives when diving with a computer without using information provided by the computer to help you make your planning decisions? Ideally you should invest in a consultation session and/or guided dive with a qualified instructor or dive master and get some coaching on dive computer use. Unfortunately I get the impression that your limited budget and "price sensitivity" may prevent you from doing this. You are certainly doing the right thing by taking ownership over your own profile and safety by using a dive computer. Please consider investing additional time, and money if required, to make sure you know how to safely use this instrument.