a pushy sales pesron is usually a person who is not good at selling. they don't listen but have a preconceived notion of what you want, based on their training or product knowledge.
a good sales person will not push you to buy something you don't want, but will listen and suggest to you things that you do want and things that will improve what you want (thereby potentially increasing the sale)
an excellent sales person will listen to what you want, improve on it and then convince you that you do actually want the product you didn't want before... and if they are superb you'll think wanting that other product was your own idea.
in all honesty, if someone tries to push something on me that i don't want i'll immediately get suspicious and back off. someone who tries to tell me i want something totally different to what i'm looking for, but then can't demonstrate WHY i should want it without resorting to price/value for money arguments usually demonstrates that they aren't listening to me. (i might like to add that i rate service and product above price points. i rarely choose to buy something because it's the cheapest option.) sure, a quad may be better value than 3 eyeshadows, but if i only like 2 eye shadows in the quad then i've wasted my money.
i have to feel like i can trust the SA to give me good advice and good service. if i don't feel that, then they don't get my sale. end of story.