Putting offer on first home, no agent.. tips? and offer suggestion

[Eric P.]

Wife and I are ready to put an offer on a home we are in love with.  We've been watching the market for months and this home fits our needs the best.  The home has been on the market over 100 days, has "motivated sellers", no offers yet, and I'm using a family member real estate attorney and foregoing the buyers side agent.  This should save the seller $12k-$14k worth of buyer side commission which should allow me to ask for a lower price.  Any additional suggestions?

quick property info:  asking $425k.  Could use new siding above the garage and one or 2 other areas (maybe whole house).  A similar house in the neighborhood was just price dropped to $415k.  The home next door sold 2 years ago for $395k and is extremely comparable. 

I'm saying a fair value is about $405,00 based on the similar properties.  I'd want $10k off for the siding and a few other little things, then about $8,000 for closing costs from the commissions savings.  So $395,000 and $8,000 in closing sound fair?  Should I start a little lower so I leave myself more room to come up or is that too aggressive?

Any suggestions would be great!