You are not getting a discount for that.

, but that if I don't use a broker the seller won't discount the price of the apartment (bc they don't want any other buyers in the building to think I got a better price).

Can I get a discount if I help you?""

But as @Chris Hopper said there are condos which can work even with HOA fees if they are bought discounted.

@Robert Brunson What’s the military discount at Lumber?

You can get pretty decent discounts doing it that way over a typical buyer that needs to get a loan. 

Another friend offered his 30% OFF discount voucher for Lowes & 15% OFF coupon HomeDepot (some kind of employee rewards of the month at his company).

If everything you say is accurate, I'm not sure why the seller would sell at a discount.

A lot of forum members are experts in their respective fields related to real estate investing, whether that is real estate sales, wholesaling, flipping, buy and hold investing, lending, self-directed IRA and Solo 401k investing, or tax and legal guidance.There are some pretty nice discounts on many products and services offered as Perks to BP members that you might want to check out: https://www.biggerpockets.com/perks/proThe site has quite a few tools that can be helpful for new members.

Even if you subtract for RE commission, closing costs and discount the property for a fast sale, you should clear around $50-55k.3 - It would take you around 17 years of perfect tenants to reach $51 k in cash flow.4 - If you invest the $51k in flips, make only 10% per flip, and do two a year, and don't reinvest your profits...just keep reinvesting the seed money ($51k), you could profit over $5k/year...double what you would be getting in CF if you left it as a rental.5 - Now, if you reinvested your profit back into the flips, you would be compounding you profits.6 - 10 years of compounded profits, at 10%/flip...2/yr = over$280k in profit7 - After your accumulated profit reaches the point when added to the original seed money equals enough  to when flipped, you can use just the profit to buy rentals.8 - keep flipping the enlarged seed money.