As per my knowledge (and I don't consider my knowledge as up-to-date), most of the Linux-based version of the netbooks are lacking in configuration (e.g. lesser capacity battery or hard disk or no bluetooth) as compared to windows counterparts. And the difference between them is hardly 1 to 1.5K. So, it may not be worth going for Linux netbooks based on price/performance ratio.
If there is a deal for linux netbook with substantial difference in price, then only it will make sense to opt for it.
There is a "Samsung NetBook ND10" available on Ebay for 18K. This is a DOS version, and will suit your purpose as you intend to install Windows XP on it. With proper coupons you might be able to get it for 17K.