There are really two parts to your question: 1) buy a back-inflation BCD; 2) buy a Zeagle Ranger. To the first - YES, go for it. It (back-inflation) is where you will very likely want to be in the future if you become a diver. The chances that it will be 'not the style I'll end up liking' are quite small. As to the second, there are pros and cons. The Ranger is an excellent BCD, in terms of materials and workmanship. My first BCD was a Ranger and I loved it - it fit like a finely tailored sportcoat and was very comfortable in the water. I still have it ~ 16 years later, but haven't dove it in a long time. The downside is that the standard bladder (44 lbs) has far more lift than you need for single cylinder diving, even if you are diving cold water, with a thick exposure suit, requiring ample amounts of lead. That extra lift capacity sounds like a good thing, but it isn't. It means that you can have a small air bubble floating around in the underfilled bladder, making trim optimization very challenging. In additional, it is a fabric BCD - it is positively buoyant, and you 'pay the price' for that buoyancy by the need to add lead to compensate.
If you are offered a truly great deal - and for me a 'great deal' on a used Ranger would have to be $125 or less on a unit that it is very good condition - in that case it would be worth it. A 'great deal', by the way, is NOT a $350 price on a used Ranger simply because 'it sells new for $790, so you are paying less than half price!'. You can do MUCH better.