Dear wwphilately
You can list in US Dollars by listing on www.ebay.com and it is possible to list using the same user ID that you have. The fees for this listing will apply of the site that you are listing but your billing currency remains the same.
If you list on ebay India and select the International Shipping option, your listing also appears on eBay.com. In the item page, the approx. US Dollar value is shown against INR price that you have mentioned.
Out of the two, the former option is better if you want to list only in US Dollars.
Regards
Amarjit
Thanks
Amar