If you can truly get an a10 for $450, it likely is your absolute best deal.
(do we have a link for the deal for the refurb laptop?)
The A10 actually has about as good of a GPU built into it as you will be able to afford with this budget.
The only issue is dealing with refurb. Refurb is a toss-up... some of them are just barely opened units where the battery didn't work or a piece of RAM was bad. (easy replacement) Others have major problems. (bad paste job andgot cooked, someone dropped it, etc.)