Recently, Steve Herschbach wrote a good article what might be one of the lowest cost detectors that could be used for nugget hunting. Here is that link;
http://www.nuggetshooter.ipbhost.com/index.php?showtopic=12820
Unfortunately, people have a tendency to forget the original statement Steve made and that is, to find the lowest cost new detector that might work for nugget hunting. Now, over the years I have used several Tesoro's for nugget hunting including some of their models normally sold as coin detectors and had success with most of them. The trick is to learn the benefits and limitations of each detector as well as the best technique to use to set up the detector. On the other side of the coin I have not used the Vaquero so I can't comment specifically on this particular model.
Now, given the lack of particular information, it is extremely difficult to recommend any particular detector. The reason is people are diffent and as such, their preferences in detectors are quite different. What I may like, you may not and visa versa. Then, there is the price a person wants or is willing to pay. Of course, the idea of new versus used is also something to be considered.
Finally, there are the subtle differences which give each detector a little advantage over others.
So, the ultimate decision has to be made by the potential owner. On the down side, anyone just getting started has no idea of what they want because, in most cases, they do not know the differences or even what is available.
In your case, it would help to know if you prefer buying new or would consider a used unit. Then there is the general price range which can alter or limit just what might be within the range you are willing to pay.
Next, it helps to know more about the general area you will hunt. In most cases, this requires you talk to a few active and, hopefully, experienced detector operators in the area to find out just what works and why. Also, you might ask around and see if there is an active local prospecting club. Many times you can obtain a wealth of information from some of their members.
As for a couple of simple reasons of why it helps to ask are; the level of mineralization and how difficult it is to deal with; the issue of hotrocks and how frequent they are as well as the type. Then there is the trash level one has to contend with; and also, one really needs to know the more typical size of gold one might expect to find.
Obviously, there are other questions, but even these few are more than enough to confuse a novice just getting started. It does help if you are familiar with using a detector for coin hunting, but even that can be a disadvantage because there generally is a distinct difference in methods that are applied.
I hope I haven't confused you too much.
Reg