You are a little early, although I can understand, in looking for hotels in NYC at this point for October.
That having been said, let me suggest the Sheraton Hotel and Towers on 7th and 52nd. My wife and I have stayed there recently and paid $179 per night (you have to add all sorts of taxes to this) for a decent room. We made the reservations on line via the Sheraton site.
The location is good. There is a subway right on the same corner, and buses go downrown right across the street. You are only a few blocks from Times Square and Rockerfeller Center. there's a decent deli across the street for breakfast and late night noshing (a New York term for eating).
We usually stay at the Renaissance in Manhatten using our Marriott Rewards points. Rooms ther are typically $279 and up. This last time there were no vacancies, so we opted for the Sheraton.
If you want a good basic place without a lot of frills, try the Ramada Inn in the east 30's (I think). Less than $100 per night. Not the most convenient of locations though.
Another thought is the Hilton on 6th Avenue. Just a couple of blocks from the Sheraton I mentioned above.
The upper East and West sides are really not convenient to the center of Manhatten, but if you're willing to take taxis, that's not a consideration.
October is a busy time in Manhatten, with the theatre and all, so bargains on rooms might be hard to find.
I'd also go t biddingfortravel.com and read thorugh what they have to say about Manhatten hotels. Again, I think you're early for October.
Being a former New Yorker, I worked on 50th and 6th Avenue (Time-Life Building for many years) but I've been out of touch with Manhattan hotels for over 12 years. I'm sure there are many new hotels since I left town.
I know that the upper west and east side are harder to get around, even with subways, anything in the 50's is ideal for either going uptown or downtown. We were looking maybe on the east side in the 50's, but not so close to the UN.
I'll check out biddingfortravel.com. I've never been on that site.
Thanks again, looking forward to being a New Yorker once again and I can taste the pastrami on rye with mustard as I write this.