I'm selling my house worth about 400k without agent, anybody know the
"Cost of Using My Own Lawyer VS Using Buyer Lawyer"

I only know this
Lawyer fee for S&P
First RM150k = 1%
Subsequent up to RM1 million = 0.7%

Roughly how much using "Own Lawyer VS Buyer Lawyer", difference in cost.

Never use same lawyer as the buyers. Big no no. Appoint your own lawyer. You need the lawyer to protect your interest in the snp draft. If you don't have any idea who to look for, Can always use mine

The cost won't differ much between using your own and buyers lawyer

though I have done this before, its usually not advisable if you are NOT familiar with SPAs..

if you use the buyer's lawyer ;

I) you will not be legally represented so you are your own "lawyer" and because of this, you do not pay
the legal fee ..ie zero..but if you are still servicing the loan, you will need to pay the buyer's lawyer to discharge
the loan for you and file in your tax return - so all in all maybe around 1k only for disbursements etc....savings to you will be a few thousand
( based on 400K would be 3k plus)