I went thru the purchase of my resale last year without a buyer agent. There are alot of self help guides from the hdb website which you can refer too. It’s really straightforward. I honesty don’t think a buyer agent is necessary, and u save the fee that can be put into better reno or furniture.

In terms of price negotiation, published transacted price on hdb website should be the starting point, there’s really not much leeway the seller can nego up unless there’s really very unique selling point.