It's been a couple of years now I've been using Fiverr to outsource some boring tasks.
In the past years, after discussing the tasks, I've always been asked, "What is your budget, sir?" and I HATE IT.
Why are you asking for my budget? My budget could be 100K up, but this is not the point. WHAT IS YOUR PRICE? Show some pride in what you do.
This sentence makes me so nervous I immediately close the door to work with those people.
This is normal depending on the type of service.
If someone is selling SET specific products, then they shouldn't ask what your budget is since it doesn't matter. If it's a service, then they need to know your budget. It's an absolute must with new clients to figure out if you're on the same page and what level of service you can offer them.
I always ask this question. I'm not going to waste my time going deep with someone that has a budget of $100/mo.
It's also important to know so that you can tailor your actual advice to them.
Although, I don't usually say "What's your budget" unless it's someone who's just asking me to pick products for them so I need to know what they want to spend. I would generally ask "How much are you wanting to initially allocate for this project?" Which is a far better way to word it. You aren't asking their max total budget which is asking someone to put ALL cards on the table. You're just asking them what they are comfortable with as an initial spend.
Sir is unprofessional ? How do you address a potential client?
Do you say like: Hey fool / no knowledge person, what are the work details?
"Sir" is awful. Just awful.
Anyone who says "sir" to me I picture them as a beggar who's absolutely desperate for my business.
I am from the USA and say "sir" in real life.
It's not that uncommon and is often symbolic of respect.
Not sure why some people here don't like it.
Fuck respect.
Respect has to be EARNED. You don't just give it out to someone who you're trying to please.
What should be on your mind is them respecting you, not you respecting them.
People don't hand over big sums of money to people calling them "Sir". They point them to their luggage to have it carried up to their room.
People hand over money to someone that has very high self-respect and self-confidence, and calling a stranger "Sir" implies you are supplicant to them.
The only people you should be calling "Sir" are those you *really* feel humble towards. Someone who has gone out of their way to help you with something is a good example. Someone who has achieved something significant in your field.
It should be GENUINE. A genuine feeling of humbleness and respect from you. Doing that towards a stranger, or someone you want to buy from you is very weak/needy.
I address my clients however I feel. I view them as equals. Other business people. I call them mate, bro, buddy or their name depending on the vibe I get and their country. AU/UK I say mate. US/CA/some other countries, buddy. And people who use bro, I use bro back. Or, I use bro if I really like the person.
Actually, a lot of people still use these expressions and it's totally normal, calling someone SIR is a sign of respect.
EDIT:
as for asking clients what their budget is, personally, I do that with the ones that have +$10k projects otherwise I'd provide a quote for the work.
"a lot of people" and "normal" is not really what you want as your compass.
Again, this "respect" thing turns my stomach.
Are you a fucking boss, or are you a valet?
Save your "Sir" and when you do use it, it'll have a LOT of power.
It's like dating a girl and constantly telling her how beautiful she looks. It's fucking lame.

She will think you are needy.
Be self-confident, have self-respect. Respect her, or your client as an equal, and when you DO drop a "Sir" or a "you look beautiful" it will have power.
Also, I would never use "sir" online, ever under any circumstances because it has such negative connotations. As soon as someone calls me "Sir" I know they are a $5 seller. If used, it should be sparingly for impact and when earned, and with the right tonality.