Opticron has an unfortunately confusing model naming nomenclature and does frequent "refreshes" as they upgrade models or swap to different production, so it can be difficult to keep up. Generally the "VHD" and "Imagic" labels are reserved for their upper crust optics which are outsourced from Japan (instead of China for the cheaper models).
As best I understand it:
- the DBA VHD (double hinge) was their top binocular a few years ago
- the DBA VHD+ is the same binocular but with newer, slightly upgrade coatings (so incrementally brighter)
- the BGA VHD is the current model, and is a totally different binocular that is largely identical to the Tract Toric UHD model stateside
If you spend some time here in the Opticron subforum you can find discussion of all three. As far as I can tell they are all excellent and the minor differences between them would be irrelevant for someone in your position.... in other words, all three would be a huge upgrade over the assemblage of inexpensive bins you have now and I would just worry about which of the three you can find in budget rather than sweating any tiny differences. The ergonomics (double hinge vs single central bridge) are likely a bigger factor between the three than the optics.
Don't assume that because you find one priced higher than the other that it is much better, especially when looking at older/discontinued models. Because of discounting (or lack thereof) the sale price may not reflect the actual quality, so it's safer to google a bit and see if you can backtrack the actual full retail price which will give a better indicator of quality level.