I need tires for my 2005 A4 quattro. Every time I go and get a quote I'm asked what kind of vehicle I have, and once I say "Audi" they recommend for me to get the more expensive tires. Do I need to get the more expensive tires, or just regular tires?
Perhaps you would be better served by going in with some specific questions rather than allowing a salesman (who might be paid on commission) to drive your purchase.
For example, when I search Tire Rack for 2005 Audio A4 Quattro (Base model), I see many tires ranging upwards from $265 USD. When I purchased my snow tires recently, I asked the shop that I wanted to purchase them from for a quote on those specific tires. They gave me an acceptable price and I've been very satisfied with the performance.
All that said, this is shopping advice and I would normally point you towards the chat as a better place to ask open-ended opinion or shopping themed questions.
As long as you fit the same size tyres, it doesn't matter all that much. "Premium" tyres don't make as much noise when you're cruising (e.g. the Geolandar tyres on the Subaru Forester is jokingly called the GeoSquealers) and they might offer a bit better handling in dry or wet conditions, but if you don't drive like a maniac, you probably won't notice the difference.
As a bonus, "cheap" tyres normally last longer because they're made from a harder compound.
Audi generally relates to RWD or AWD cars with more power than the general drive around car that most people buy. Hence the most people recommend more expensive tyres to handle the extra power. However expensive tyres and cheap tyres can be bought for any car. It all depends on the specification you need.
Best thing to do is search online with your tyre size. Look at review if you care about the tyres you want. Or if not then go for cheapest. Keeping in mind cheap tyres cannot in most cases be compared to the premium brands.
The key thing to remember when buying tyres is the bit that can be missed when buying cheap tyres.
Provided that the tyres you fit have a sufficient speed rating and load rating and are certified for sale and use in your location, it doesn't matter how much you spend.
Cheap tyres generally provide poorer levels of grip so if you're using the car for track or competition use then don't fit budget tyres but for everyday conservative driving, budget tyres should be fine.