I'm surprised that bothered you. Most salespeople don't, or if they do, very little. It's to your advantage. The Internet is your friend, not most of the sales people ( although there are some).
I'd be estatic if they let me alone. Many salespeople if they have any thought you're not serious or they feel you aren't dressed for the part will rush you based on their assumption. Try looking at new MH's when a dealer has a open house. They'll drop you in a heart beat if "they think" it isn't going to happen today.
You'll learn a lot more doing the research on your own. Then use that to your advantage in the negotiation process.