No, I wouldn't spend $130 on a GTS 450, nor would I spend $149 for a GTX 260, nor would I spend $155 for a GTX 460.
In my post I said I could get a GTS for 450 for $100 before taxes. I'm friends with a small vendor locally who will have these cards in stock on Tuesday.
This shop doesn't carry GTX 260's Super OCs, and his GTX 460's start at around $169.99 and they don't have rebates.
So, when I asked is the GTS 450 a better PhysX card over my 9800 GTX+ because I can buy one out of my pocket for $50 (have someone who wants to buy my 9800 GTX+, offering it to them for $50) the question was rather straight forward. I wasn't asking for alternatives (that were more costly to me ontop of that used more power, created more heat, and would be bulkier.)
I'd want a smaller card for my PhysX needs and was curious - would this card be better than a 9800 GTX+. If in the end it wasn't I could turn around and re-sell it for $100 easy.