RWS/Diana 52 Investment ?

So I have an acquaintance who has an RWS Diana model 52 in .177 cal for sale. 
My question. Should I buy this ? My dilemma. I don’t need this. The seller is asking top dollar. I believe the gun is in excellent condition and new. I know this person only buys top of line products and takes excellent care of what they own. 
I prefer low power / backyard friendly springers. This gun is not that. But I do realize the quality and accuracy that this gun is capable of. 
Quality air rifles don’t come up for sale locally very often around here. Does my dilemma make sense ? It’s a lot of cash for a quality product that I don’t really need.
Should I pass on this deal. Or could it be a good investment as far as air rifles go. 
Thanks 
 
At top dollar, its a NO for me, dawg. 

It's the wrong caliber for most people in that platform. 

An investment to sell is a NO in my opinion. If you want to keep it to shoot, detune it a bit and use heavier pellets and they are pretty good shooters and excellent hunting guns. 

If it was a .22, and sensible money, I may go for it. But in .177 and for primo money, nah. 

Just my take. 
 
Hello If you don't need it (does not fit your needs) and it is not priced where its to good to pass up, you might be better off passing and buying some thing you really want. I have done just that and a few months later looking at the item and saying "why" and usually passing it off at a loss as I try to be fair with prices of items I sell especially when used. Well just my opinion hope it helps Eric.
 
I get it that the .22 is bigger, heavier and will have more knockdown power. What I don't get is why so many shun the .177 caliber. I am far from an expert on the ballistics between the 2 most common pellets but I do think and could be way off the lighter 177 if fired from the same model rifle should go faster than the 22 cal. My Diana 54 is in 177 and very accurate as far as I can tell so far plus it dispatches small critters, chipmunks, and red and grey squirrels, in my yard at 30 yards just fine. I do suspect the 22 would be much preferred if I was after larger critters such as rabbits and skunks. I also think that both calibers should be fine for punching paper. Educate me on this or point me to discussions that can help me understand.
 
I get it that the .22 is bigger, heavier and will have more knockdown power. What I don't get is why so many shun the .177 caliber. I am far from an expert on the ballistics between the 2 most common pellets but I do think and could be way off the lighter 177 if fired from the same model rifle should go faster than the 22 cal. My Diana 54 is in 177 and very accurate as far as I can tell so far plus it dispatches small critters, chipmunks, and red and grey squirrels, in my yard at 30 yards just fine. I do suspect the 22 would be much preferred if I was after larger critters such as rabbits and skunks. I also think that both calibers should be fine for punching paper. Educate me on this or point me to discussions that can help me understand.

In this case, it's just that the powerplant in this particular model is better suited for the .22 I

And since the OP was interested in the gun being an "investment", meaning it will be desirable or at least easy to sell down the road, he would probably be better served with a .22 caliber. 

That's my take. And that's coming from a huge fan of the .177 :)